Common Weakness Enumeration

CWE-379

Allowed

Creation of Temporary File in Directory with Insecure Permissions

Abstraction: Base · Status: Incomplete

API response cwe.mitre.org

The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.

118 vulnerabilities reference this CWE, most recent first.

GHSA-23X4-M842-FMWF

Vulnerability from github – Published: 2021-05-11 00:04 – Updated: 2023-06-30 20:30
VLAI
Summary
Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI-Generator online generator
Details

Impact

On Unix like systems, the system's temporary directory is shared between all users on that system. A collocated user can observe the process of creating a temporary sub directory in the shared temporary directory and race to complete the creation of the temporary subdirectory.

This vulnerability is local privilege escalation because the contents of the outputFolder can be appended to by an attacker. As such, code written to this directory, when executed can be attacker controlled.

openapi-generator-online creates insecure temporary folders with File.createTempFile during the code generation process. The insecure temporary folders store the auto-generated files which can be read and appended to by any users on the system.

Vulnerable Code

https://github.com/OpenAPITools/openapi-generator/blob/c6530519975341d7784a252132b2f0854f488901/modules/openapi-generator-online/src/main/java/org/openapitools/codegen/online/service/Generator.java#L184-L187

This vulnerability exists due to a race condition between the deletion of the randomly generated temporary file and the creation of the temporary directory.

File outputFolder = File.createTempFile("codegen-", "-tmp"); // Attacker knows the full path of the file that will be generated
// delete the file that was created
outputFolder.delete(); // Attacker sees file is deleted and begins a race to create their own directory before the code generator
// and make a directory of the same name
// SECURITY VULNERABILITY: Race Condition! - Attacker beats the code generator and now owns this directory
outputFolder.mkdir();

Patches

The issue has been patched by changing the underlying logic to use Files.createTempFile and has been released in the v5.1.0 stable version.

This vulnerability has the same root cause as CVE-2021-21363 from the swagger-api/swagger-codegen project as this project and that one both share the same original source tree. See: https://github.com/swagger-api/swagger-codegen/security/advisories/GHSA-pc22-3g76-gm6j

For more information

If you have any questions or comments about this advisory: * Open an issue in OpenAPI Generator Github repo * Email us at security@openapitools.org

Severity
9.3 (Critical)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.openapitools:openapi-generator-online"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-21428"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-269",
      "CWE-377",
      "CWE-378",
      "CWE-379",
      "CWE-668"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-05-10T18:52:04Z",
    "nvd_published_at": "2021-05-10T19:15:00Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\n\nOn Unix like systems, the system\u0027s temporary directory is shared between all users on that system. A collocated user can observe the process of creating a temporary sub directory in the shared temporary directory and race to complete the creation of the temporary subdirectory.\n\nThis vulnerability is local privilege escalation because the contents of the outputFolder can be appended to by an attacker. As such, code written to this directory, when executed can be attacker controlled.\n\nopenapi-generator-online creates insecure temporary folders with `File.createTempFile` during the code generation process. The insecure temporary folders store the auto-generated files which can be read and appended to by any users on the system.\n\n### Vulnerable Code\n\nhttps://github.com/OpenAPITools/openapi-generator/blob/c6530519975341d7784a252132b2f0854f488901/modules/openapi-generator-online/src/main/java/org/openapitools/codegen/online/service/Generator.java#L184-L187\n\nThis vulnerability exists due to a race condition between the deletion of the randomly generated temporary file and the creation of the temporary directory.\n\n```java\nFile outputFolder = File.createTempFile(\"codegen-\", \"-tmp\"); // Attacker knows the full path of the file that will be generated\n// delete the file that was created\noutputFolder.delete(); // Attacker sees file is deleted and begins a race to create their own directory before the code generator\n// and make a directory of the same name\n// SECURITY VULNERABILITY: Race Condition! - Attacker beats the code generator and now owns this directory\noutputFolder.mkdir();\n```\n\n### Patches\nThe issue has been patched by changing the underlying logic to use `Files.createTempFile` and has been released in the v5.1.0 stable version.\n\nThis vulnerability has the same root cause as CVE-2021-21363 from the `swagger-api/swagger-codegen` project as this project and that one both share the same original source tree.\nSee: https://github.com/swagger-api/swagger-codegen/security/advisories/GHSA-pc22-3g76-gm6j\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [OpenAPI Generator Github repo](https://github.com/openAPITools/openapi-generator/)\n* Email us at [security@openapitools.org](mailto:security@openapitools.org)",
  "id": "GHSA-23x4-m842-fmwf",
  "modified": "2023-06-30T20:30:26Z",
  "published": "2021-05-11T00:04:40Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-23x4-m842-fmwf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/swagger-api/swagger-codegen/security/advisories/GHSA-pc22-3g76-gm6j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21428"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenAPITools/openapi-generator/pull/8788"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/OpenAPITools/openapi-generator"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenAPITools/openapi-generator/blob/c6530519975341d7784a252132b2f0854f488901/modules/openapi-generator-online/src/main/java/org/openapitools/codegen/online/service/Generator.java#L184-L187"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI-Generator online generator"
}

GHSA-269Q-HMXG-M83Q

Vulnerability from github – Published: 2022-05-10 08:46 – Updated: 2022-05-10 08:46
VLAI
Summary
Local Information Disclosure Vulnerability in io.netty:netty-codec-http
Details

Description

GHSA-5mcr-gq6c-3hq2 (CVE-2021-21290) contains an insufficient fix for the vulnerability identified.

Impact

When netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled.

This only impacts applications running on Java version 6 and lower. Additionally, this vulnerability impacts code running on Unix-like systems, and very old versions of Mac OSX and Windows as they all share the system temporary directory between all users.

Vulnerability Details

To fix the vulnerability the code was changed to the following:

    @SuppressJava6Requirement(reason = "Guarded by version check")
    public static File createTempFile(String prefix, String suffix, File directory) throws IOException {
        if (javaVersion() >= 7) {
            if (directory == null) {
                return Files.createTempFile(prefix, suffix).toFile();
            }
            return Files.createTempFile(directory.toPath(), prefix, suffix).toFile();
        }
        if (directory == null) {
            return File.createTempFile(prefix, suffix);
        }
        File file = File.createTempFile(prefix, suffix, directory);
        // Try to adjust the perms, if this fails there is not much else we can do...
        file.setReadable(false, false);
        file.setReadable(true, true);
        return file;
    }

Unfortunately, this logic path was left vulnerable:

        if (directory == null) {
            return File.createTempFile(prefix, suffix);
        }

This file is still readable by all local users.

Patches

Update to 4.1.77.Final

Workarounds

Specify your own java.io.tmpdir when you start the JVM or use DefaultHttpDataFactory.setBaseDir(...) to set the directory to something that is only readable by the current user or update to Java 7 or above.

References

For more information

If you have any questions or comments about this advisory:

Open an issue in netty

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.1.76.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-http"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.77.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-24823"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-378",
      "CWE-379",
      "CWE-668"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2022-05-10T08:46:50Z",
    "nvd_published_at": "2022-05-06T12:15:00Z",
    "severity": "MODERATE"
  },
  "details": "### Description ###\n[GHSA-5mcr-gq6c-3hq2](https://github.com/netty/netty/security/advisories/GHSA-5mcr-gq6c-3hq2) (CVE-2021-21290) contains an insufficient fix for the vulnerability identified.\n\n### Impact ###\n\nWhen netty\u0027s multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled.\n\nThis only impacts applications running on Java version 6 and lower. Additionally, this vulnerability impacts code running on Unix-like systems, and very old versions of Mac OSX and Windows as they all share the system temporary directory between all users.\n\n### Vulnerability Details ###\n\nTo fix the vulnerability the code was changed to the following:\n\n```java\n    @SuppressJava6Requirement(reason = \"Guarded by version check\")\n    public static File createTempFile(String prefix, String suffix, File directory) throws IOException {\n        if (javaVersion() \u003e= 7) {\n            if (directory == null) {\n                return Files.createTempFile(prefix, suffix).toFile();\n            }\n            return Files.createTempFile(directory.toPath(), prefix, suffix).toFile();\n        }\n        if (directory == null) {\n            return File.createTempFile(prefix, suffix);\n        }\n        File file = File.createTempFile(prefix, suffix, directory);\n        // Try to adjust the perms, if this fails there is not much else we can do...\n        file.setReadable(false, false);\n        file.setReadable(true, true);\n        return file;\n    }\n```\n\nUnfortunately, this logic path was left vulnerable:\n\n```java\n        if (directory == null) {\n            return File.createTempFile(prefix, suffix);\n        }\n```\n\nThis file is still readable by all local users.\n\n### Patches ###\n\nUpdate to 4.1.77.Final\n\n### Workarounds ###\n\nSpecify your own `java.io.tmpdir` when you start the JVM or use `DefaultHttpDataFactory.setBaseDir(...)` to set the directory to something that is only readable by the current user or update to Java 7 or above.\n\n### References ###\n\n - [CWE-378: Creation of Temporary File With Insecure Permissions](https://cwe.mitre.org/data/definitions/378.html)\n - [CWE-379: Creation of Temporary File in Directory with Insecure Permissions](https://cwe.mitre.org/data/definitions/379.html)\n\n\n### For more information ###\n\nIf you have any questions or comments about this advisory:\n\nOpen an issue in [netty](https://github.com/netty/netty)\n",
  "id": "GHSA-269q-hmxg-m83q",
  "modified": "2022-05-10T08:46:50Z",
  "published": "2022-05-10T08:46:50Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-269q-hmxg-m83q"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-5mcr-gq6c-3hq2"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-24823"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/commit/185f8b2756a36aaa4f973f1a2a025e7d981823f1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20220616-0004"
    },
    {
      "type": "WEB",
      "url": "https://www.oracle.com/security-alerts/cpujul2022.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Local Information Disclosure Vulnerability in io.netty:netty-codec-http"
}

GHSA-2CXF-6567-7PP6

Vulnerability from github – Published: 2021-03-03 23:01 – Updated: 2021-07-08 17:02
VLAI
Summary
Local Information Disclosure Vulnerability
Details

Impact

Local information disclosure of sensitive information downloaded via the API using the API Client.

Finding

The Datadog API is executed on a unix-like system with multiple users. The API is used to download a file containing sensitive information. This sensitive information is exposed locally to other users. This vulnerability exists in the API Client for version 1 and 2. The method prepareDownloadFilecreates creates a temporary file with the permissions bits of -rw-r--r-- on unix-like systems. On unix-like systems, the system temporary directory is shared between users. As such, the contents of the file downloaded via the downloadFileFromResponse method will be visible to all other users on the local system.

Analysis of the finding determined that the affected code was unused, meaning that the exploitation likelihood is low. The unused code has been removed, effectively mitigating this issue.

This vulnerability was found due to this query that Jonathan Leitschuh contributed to the Semmle QL project.

Patches

This issue has been patched in version 1.0.0-beta.9.

See also Remove unused downloadFile helpers.

Workarounds

The recommended workaround is to specify java.io.tmpdir when starting the JVM with the flag -Djava.io.tmpdir, specifying a path to a directory with drw------- permissions owned by dd-agent.

References

For more information

If you have any questions or comments about this advisory: * Open an issue in DataDog/datadog-api-client-java
* Email us at security@datadoghq.com

Severity
3.0 (Low)
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:N/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "com.datadoghq:datadog-api-client"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0-beta.6"
            },
            {
              "fixed": "1.0.0-beta.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-21331"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-378",
      "CWE-379"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-03-03T22:58:04Z",
    "nvd_published_at": "2021-03-03T23:15:00Z",
    "severity": "LOW"
  },
  "details": "### Impact\nLocal information disclosure of sensitive information downloaded via the API using the API Client. \n\n### Finding\nThe Datadog API is executed on a unix-like system with multiple users. The API is used to download a file containing sensitive information. This sensitive information is exposed locally to other users. This vulnerability exists in the API Client for version 1 and 2. The method `prepareDownloadFilecreates` creates a temporary file with the permissions bits of `-rw-r--r--` on unix-like systems. On unix-like systems, the system temporary directory is shared between users. As such, the contents of the file downloaded via the `downloadFileFromResponse` method will be visible to all other users on the local system.\n\nAnalysis of the finding determined that the affected code was unused, meaning that the exploitation likelihood is low. The unused code has been removed, effectively mitigating this issue. \n\nThis vulnerability was found due to [this query](https://lgtm.com/query/8938575359870595124/) that [Jonathan Leitschuh](https://github.com/JLLeitschuh) contributed to the Semmle QL project.\n\n### Patches\nThis issue has been patched in [version 1.0.0-beta.9](https://github.com/DataDog/datadog-api-client-java/releases/tag/datadog-api-client-1.0.0-beta.9). \n\nSee also [Remove unused downloadFile helpers](https://github.com/DataDog/datadog-api-client-java/pull/637). \n\n### Workarounds\nThe recommended workaround is to specify `java.io.tmpdir` when starting the JVM with the flag `-Djava.io.tmpdir`, specifying a path to a directory with `drw-------` permissions owned by `dd-agent`.\n\n### References\n* [CWE-378: Creation of Temporary File With Insecure Permissions](https://cwe.mitre.org/data/definitions/378.html)\n* [CWE-379: Creation of Temporary File in Directory with Insecure Permissions](https://cwe.mitre.org/data/definitions/379.html)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [DataDog/datadog-api-client-java](https://github.com/DataDog/datadog-api-client-java)\t\n* Email us at [security@datadoghq.com](mailto:security@datadoghq.com)",
  "id": "GHSA-2cxf-6567-7pp6",
  "modified": "2021-07-08T17:02:28Z",
  "published": "2021-03-03T23:01:17Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/DataDog/datadog-api-client-java/security/advisories/GHSA-2cxf-6567-7pp6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21331"
    },
    {
      "type": "WEB",
      "url": "https://github.com/DataDog/datadog-api-client-java/releases/tag/datadog-api-client-1.0.0-beta.9"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Local Information Disclosure Vulnerability"
}

GHSA-2J93-F5F2-6WJX

Vulnerability from github – Published: 2024-03-13 21:31 – Updated: 2024-03-13 21:31
VLAI
Details

Improper access control in the installer for Zoom Rooms Client for Windows before version 5.17.5 may allow an authenticated user to conduct a denial of service via local access.

Severity
7.2 (High)
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2024-24693"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-284",
      "CWE-379"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-03-13T20:15:07Z",
    "severity": "HIGH"
  },
  "details": "Improper access control in the installer for Zoom Rooms Client for Windows before version 5.17.5 may allow an authenticated user to conduct a denial of service via local access.\n\n",
  "id": "GHSA-2j93-f5f2-6wjx",
  "modified": "2024-03-13T21:31:02Z",
  "published": "2024-03-13T21:31:02Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-24693"
    },
    {
      "type": "WEB",
      "url": "https://www.zoom.com/en/trust/security-bulletin/zsb-24009"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-37F3-8H34-H4XF

Vulnerability from github – Published: 2023-11-01 18:30 – Updated: 2023-11-01 18:30
VLAI
Details

A vulnerability was found in insights-client. This security issue occurs because of insecure file operations or unsafe handling of temporary files and directories that lead to local privilege escalation. Before the insights-client has been registered on the system by root, an unprivileged local user or attacker could create the /var/tmp/insights-client directory (owning the directory with read, write, and execute permissions) on the system. After the insights-client is registered by root, an attacker could then control the directory content that insights are using by putting malicious scripts into it and executing arbitrary code as root (trivially bypassing SELinux protections because insights processes are allowed to disable SELinux system-wide).

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2023-3972"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-379",
      "CWE-668"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-11-01T16:15:08Z",
    "severity": "HIGH"
  },
  "details": "A vulnerability was found in insights-client. This security issue occurs because of insecure file operations or unsafe handling of temporary files and directories that lead to local privilege escalation. Before the insights-client has been registered on the system by root, an unprivileged local user or attacker could create the /var/tmp/insights-client directory (owning the directory with read, write, and execute permissions) on the system. After the insights-client is registered by root, an attacker could then control the directory content that insights are using by putting malicious scripts into it and executing arbitrary code as root (trivially bypassing SELinux protections because insights processes are allowed to disable SELinux system-wide).",
  "id": "GHSA-37f3-8h34-h4xf",
  "modified": "2023-11-01T18:30:33Z",
  "published": "2023-11-01T18:30:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-3972"
    },
    {
      "type": "WEB",
      "url": "https://github.com/RedHatInsights/insights-core/pull/3878"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6264"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6282"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6283"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6284"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6795"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6796"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6798"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:6811"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2023-3972"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2227027"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-4625-4J76-FWW9

Vulnerability from github – Published: 2026-04-30 18:34 – Updated: 2026-05-13 16:27
VLAI
Summary
OpenTelemetry's disk retry default temp path enables local blob injection via OTLP Exporter
Details

Summary

The OTLP disk retry feature in OpenTelemetry.Exporter.OpenTelemetryProtocol silently fell back to Path.GetTempPath() when OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk was set but OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH was not configured.

The exporter stored and loaded *.blob files under fixed, signal-named subdirectories (traces, metrics, logs) beneath that shared temporary root path.

On multi-user systems where the temporary directory is accessible to other local accounts, this exposed three attack surfaces:

  • Blob injection (integrity): an attacker could write crafted *.blob files into the predictable path; the exporter picks them up on the next retry cycle and forwards them to the configured OTLP endpoint under the application's identity.
  • Telemetry disclosure (confidentiality): an attacker reads *.blob files written by the application between export failures, recovering encoded telemetry payloads (spans, metric data points, log records).
  • Resource exhaustion (availability): an attacker deposits numerous or oversized blob files, degrading retry-loop performance or consuming disk space.

Details

Preconditions

  1. OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY is set to disk.
  2. OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH is not set, causing the exporter to resolve the blob storage root using the System.IO.Path.GetTempPath() API.
  3. A local attacker has read or write access to the process' temporary directory (e.g., /tmp on Linux, or %TEMP% on a multi-user Windows installation).

Exploit path

  1. A target application starts with OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk and no explicit blob directory. The exporter resolves the storage root to Path.GetTempPath(), producing paths such as %TEMP%\traces, %TEMP%\metrics, and %TEMP%\logs (or /tmp/traces etc. on Linux).
  2. Injection scenario: before or during the application's retry window, an attacker writes crafted *.blob files into one of those signal subdirectories. On the next retry interval (by default every 60 seconds), OtlpExporterPersistentStorageTransmissionHandler scans the directory, loads the attacker-supplied blobs, and forwards them to the configured OTLP endpoint using the application's identity and transport credentials.
  3. Disclosure scenario: the attacker reads *.blob files that the application wrote after a transient export failure, recovering the full serialized telemetry payloads (spans, metric data points, or log records in Protobuf encoding).
  4. DoS scenario: the attacker deposits a large number of oversized blob files in the temporary subdirectories, causing the retry loop to consume excess CPU/IO processing them, potentially exhausting available disk space.

Mitigations

If an immediate upgrade to a patched version is not possible:

  1. Avoid enabling disk retry in shared environments.
  2. Configure a dedicated directory with strict ACL/ownership and least privilege.
  3. Ensure the directory is not shared across tenants/users.
  4. Monitor for unexpected *.blob files or abnormal retry backlog growth.

Resources

Severity
6.5 (Medium)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.15.2"
      },
      "package": {
        "ecosystem": "NuGet",
        "name": "OpenTelemetry.Exporter.OpenTelemetryProtocol"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.8.0"
            },
            {
              "fixed": "1.15.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42191"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-379"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-30T18:34:30Z",
    "nvd_published_at": "2026-05-12T20:16:41Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nThe OTLP disk retry feature in `OpenTelemetry.Exporter.OpenTelemetryProtocol` silently fell back to `Path.GetTempPath()` when `OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk` was set but `OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH` was not configured.\n\nThe exporter stored and loaded `*.blob` files under fixed, signal-named subdirectories (`traces`, `metrics`, `logs`) beneath that shared temporary root path.\n\nOn multi-user systems where the temporary directory is accessible to other local accounts, this exposed three attack surfaces:\n\n- **Blob injection (integrity):** an attacker could write crafted `*.blob` files into the predictable path; the exporter picks them up on the next retry cycle and forwards them to the configured OTLP endpoint under the application\u0027s identity.\n- **Telemetry disclosure (confidentiality):** an attacker reads `*.blob` files written by the application between export failures, recovering encoded telemetry payloads (spans, metric data points, log records).\n- **Resource exhaustion (availability):** an attacker deposits numerous or oversized blob files, degrading retry-loop performance or consuming disk space.\n\n### Details\n\n#### Preconditions\n\n1. `OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY` is set to `disk`.\n2. `OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH` is not set, causing the exporter to resolve the blob storage root using the `System.IO.Path.GetTempPath()` API.\n3. A local attacker has read or write access to the process\u0027 temporary directory (e.g., `/tmp` on Linux, or `%TEMP%` on a multi-user Windows installation).\n\n#### Exploit path\n\n1. A target application starts with `OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk` and no explicit blob directory. The exporter resolves the storage root to `Path.GetTempPath()`, producing paths such as `%TEMP%\\traces`, `%TEMP%\\metrics`, and `%TEMP%\\logs` (or `/tmp/traces` etc. on Linux).\n2. **Injection scenario:** before or during the application\u0027s retry window, an attacker writes crafted `*.blob` files into one of those signal subdirectories. On the next retry interval (by default every 60 seconds), [`OtlpExporterPersistentStorageTransmissionHandler`](https://github.com/open-telemetry/opentelemetry-dotnet/blob/c724f4bd6fd88e9a599af1668bf7af9487155b62/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/Transmission/OtlpExporterPersistentStorageTransmissionHandler.cs) scans the directory, loads the attacker-supplied blobs, and forwards them to the configured OTLP endpoint using the application\u0027s identity and transport credentials.\n3. **Disclosure scenario:** the attacker reads `*.blob` files that the application wrote after a transient export failure, recovering the full serialized telemetry payloads (spans, metric data points, or log records in Protobuf encoding).\n5. **DoS scenario:** the attacker deposits a large number of oversized blob files in the temporary subdirectories, causing the retry loop to consume excess CPU/IO processing them, potentially exhausting available disk space.\n\n### Mitigations\n\nIf an immediate upgrade to a patched version is not possible:\n\n1. Avoid enabling disk retry in shared environments.\n2. Configure a dedicated directory with strict ACL/ownership and least privilege.\n3. Ensure the directory is not shared across tenants/users.\n4. Monitor for unexpected `*.blob` files or abnormal retry backlog growth.\n\n### Resources\n\n- [#7106](https://github.com/open-telemetry/opentelemetry-dotnet/pull/7106)",
  "id": "GHSA-4625-4j76-fww9",
  "modified": "2026-05-13T16:27:20Z",
  "published": "2026-04-30T18:34:30Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-4625-4j76-fww9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42191"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-telemetry/opentelemetry-dotnet/pull/7106"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-telemetry/opentelemetry-dotnet/commit/78dffdc5ebdf3dc090fdb94e3f1a32d3d1e26dfd"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/open-telemetry/opentelemetry-dotnet"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OpenTelemetry\u0027s disk retry default temp path enables local blob injection via OTLP Exporter"
}

GHSA-4C7Q-995F-PXPC

Vulnerability from github – Published: 2022-05-24 19:16 – Updated: 2022-05-24 19:16
VLAI
Details

Adobe Genuine Service versions 7.3 (and earlier) are affected by a privilege escalation vulnerability in the AGSService installer. An authenticated attacker could leverage this vulnerability to achieve read / write privileges to execute arbitrary code. User interaction is required to abuse this vulnerability.

Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2021-40708"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-379"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-09-29T16:15:00Z",
    "severity": "HIGH"
  },
  "details": "Adobe Genuine Service versions 7.3 (and earlier) are affected by a privilege escalation vulnerability in the AGSService installer. An authenticated attacker could leverage this vulnerability to achieve read / write privileges to execute arbitrary code. User interaction is required to abuse this vulnerability.",
  "id": "GHSA-4c7q-995f-pxpc",
  "modified": "2022-05-24T19:16:03Z",
  "published": "2022-05-24T19:16:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-40708"
    },
    {
      "type": "WEB",
      "url": "https://helpx.adobe.com/security/products/integrity_service/apsb21-81.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-4X5P-F36R-MXXR

Vulnerability from github – Published: 2026-02-02 12:31 – Updated: 2026-02-02 21:57
VLAI
Summary
mlflow Creates of Temporary File in Directory with Insecure Permissions
Details

In mlflow version 2.20.3, the temporary directory used for creating Python virtual environments is assigned insecure world-writable permissions (0o777). This vulnerability allows an attacker with write access to the /tmp directory to exploit a race condition and overwrite .py files in the virtual environment, leading to arbitrary code execution. The issue is resolved in version 3.4.0.

Severity
7.0 (High)
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "mlflow"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.0rc0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-10279"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-379"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-02T21:57:58Z",
    "nvd_published_at": "2026-02-02T11:16:16Z",
    "severity": "HIGH"
  },
  "details": "In mlflow version 2.20.3, the temporary directory used for creating Python virtual environments is assigned insecure world-writable permissions (0o777). This vulnerability allows an attacker with write access to the `/tmp` directory to exploit a race condition and overwrite `.py` files in the virtual environment, leading to arbitrary code execution. The issue is resolved in version 3.4.0.",
  "id": "GHSA-4x5p-f36r-mxxr",
  "modified": "2026-02-02T21:57:58Z",
  "published": "2026-02-02T12:31:14Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-10279"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mlflow/mlflow/commit/1d7c8d4cf0a67d407499a8a4ffac387ea4f8194a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mlflow/mlflow"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/01d3b81e-13d1-43aa-b91a-443aec68bdc8"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "mlflow Creates of Temporary File in Directory with Insecure Permissions"
}

GHSA-544P-PXVX-HQQ5

Vulnerability from github – Published: 2023-01-18 21:30 – Updated: 2023-01-18 21:30
VLAI
Details

Adobe Acrobat Reader versions 22.003.20282 (and earlier), 22.003.20281 (and earlier) and 20.005.30418 (and earlier) are affected by a Creation of Temporary File in Directory with Incorrect Permissions vulnerability that could result in privilege escalation in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2023-21612"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-379"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-01-18T19:15:00Z",
    "severity": "HIGH"
  },
  "details": "Adobe Acrobat Reader versions 22.003.20282 (and earlier), 22.003.20281 (and earlier) and 20.005.30418 (and earlier) are affected by a Creation of Temporary File in Directory with Incorrect Permissions vulnerability that could result in privilege escalation in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.",
  "id": "GHSA-544p-pxvx-hqq5",
  "modified": "2023-01-18T21:30:22Z",
  "published": "2023-01-18T21:30:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-21612"
    },
    {
      "type": "WEB",
      "url": "https://helpx.adobe.com/security/products/acrobat/apsb23-01.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-5MCR-GQ6C-3HQ2

Vulnerability from github – Published: 2021-02-08 21:17 – Updated: 2022-04-19 15:19
VLAI
Summary
Local Information Disclosure Vulnerability in Netty on Unix-Like systems
Details

Impact

When netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled.

The CVSSv3.1 score of this vulnerability is calculated to be a 6.2/10

Vulnerability Details

On unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems.

The method File.createTempFile on unix-like systems creates a random file, but, by default will create this file with the permissions -rw-r--r--. Thus, if sensitive information is written to this file, other local users can read this information.

This is the case in netty's AbstractDiskHttpData is vulnerable.

https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/codec-http/src/main/java/io/netty/handler/codec/http/multipart/AbstractDiskHttpData.java#L80-L101

AbstractDiskHttpData is used as a part of the DefaultHttpDataFactory class which is used by HttpPostRequestDecoder / HttpPostMultiPartRequestDecoder.

You may be affected by this vulnerability your project contains the following code patterns:

channelPipeline.addLast(new HttpPostRequestDecoder(...));

channelPipeline.addLast(new HttpPostMultiPartRequestDecoder(...));

Patches

This has been patched in version 4.1.59.Final.

Workarounds

Specify your own java.io.tmpdir when you start the JVM or use DefaultHttpDataFactory.setBaseDir(...) to set the directory to something that is only readable by the current user.

References

Similar Vulnerabilities

Similar, but not the same.

  • JUnit 4 - https://github.com/junit-team/junit4/security/advisories/GHSA-269g-pwp5-87pp
  • Google Guava - https://github.com/google/guava/issues/4011
  • Apache Ant - https://nvd.nist.gov/vuln/detail/CVE-2020-1945
  • JetBrains Kotlin Compiler - https://nvd.nist.gov/vuln/detail/CVE-2020-15824

For more information

If you have any questions or comments about this advisory: * Open an issue in netty * Email us here

Original Report

Hi Netty Security Team,

I've been working on some security research leveraging custom CodeQL queries to detect local information disclosure vulnerabilities in java applications. This was the result from running this query against the netty project: https://lgtm.com/query/7723301787255288599/

Netty contains three local information disclosure vulnerabilities, so far as I can tell.

One is here, where the private key for the certificate is written to a temporary file.

https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/handler/src/main/java/io/netty/handler/ssl/util/SelfSignedCertificate.java#L316-L346

One is here, where the certificate is written to a temporary file.

https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/handler/src/main/java/io/netty/handler/ssl/util/SelfSignedCertificate.java#L348-L371

The final one is here, where the 'AbstractDiskHttpData' creates a temporary file if the getBaseDirectory() method returns null. I believe that 'AbstractDiskHttpData' is used as a part of the file upload support? If this is the case, any files uploaded would be similarly vulnerable.

https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/codec-http/src/main/java/io/netty/handler/codec/http/multipart/AbstractDiskHttpData.java#L91

All of these vulnerabilities exist because File.createTempFile(String, String) will create a temporary file in the system temporary directory if the 'java.io.tmpdir' system property is not explicitly set. It is my understanding that when java creates a file, by default, and using this method, the permissions on that file utilize the umask. In a majority of cases, this means that the file that java creates has the permissions: -rw-r--r--, thus, any other local user on that system can read the contents of that file.

Impacted OS: - Any OS where the system temporary directory is shared between multiple users. This is not the case for MacOS or Windows.

Mitigation.

Moving to the Files API instead will fix this vulnerability. https://docs.oracle.com/javase/8/docs/api/java/nio/file/Files.html#createTempFile-java.nio.file.Path-java.lang.String-java.lang.String-java.nio.file.attribute.FileAttribute...-

This API will explicitly set the posix file permissions to something safe, by default.

I recently disclosed a similar vulnerability in JUnit 4: https://github.com/junit-team/junit4/security/advisories/GHSA-269g-pwp5-87pp

If you're also curious, this vulnerability in Jetty was also mine, also involving temporary directories, but is not the same vulnerability as in this case. https://github.com/eclipse/jetty.project/security/advisories/GHSA-g3wg-6mcf-8jj6

I would appreciate it if we could perform disclosure of this vulnerability leveraging the GitHub security advisories feature here. GitHub has a nice credit system that I appreciate, plus the disclosures, as you can see from the sampling above, end up looking very nice. https://github.com/netty/netty/security/advisories

This vulnerability disclosure follows Google's 90-day vulnerability disclosure policy (I'm not an employee of Google, I just like their policy). Full disclosure will occur either at the end of the 90-day deadline or whenever a patch is made widely available, whichever occurs first.

Cheers, Jonathan Leitschuh

Severity
6.2 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-http"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.1.59.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 4.0.0"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.jboss.netty:netty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 4.0.0"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-21290"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-378",
      "CWE-379",
      "CWE-668"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-02-08T20:07:45Z",
    "nvd_published_at": "2021-02-08T20:15:00Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nWhen netty\u0027s multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled.\n\nThe CVSSv3.1 score of this vulnerability is calculated to be a [6.2/10](https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N\u0026version=3.1)\n\n### Vulnerability Details\n\nOn unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems.\n\nThe method `File.createTempFile` on unix-like systems creates a random file, but, by default will create this file with the permissions `-rw-r--r--`. Thus, if sensitive information is written to this file, other local users can read this information.\n\nThis is the case in netty\u0027s `AbstractDiskHttpData` is vulnerable.\n\nhttps://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/codec-http/src/main/java/io/netty/handler/codec/http/multipart/AbstractDiskHttpData.java#L80-L101\n\n`AbstractDiskHttpData` is used as a part of the `DefaultHttpDataFactory` class which is used by `HttpPostRequestDecoder` / `HttpPostMultiPartRequestDecoder`.\n\nYou may be affected by this vulnerability your project contains the following code patterns:\n\n```java\nchannelPipeline.addLast(new HttpPostRequestDecoder(...));\n```\n\n```java\nchannelPipeline.addLast(new HttpPostMultiPartRequestDecoder(...));\n```\n\n### Patches\n\nThis has been patched in version `4.1.59.Final`.\n\n### Workarounds\n\nSpecify your own `java.io.tmpdir` when you start the JVM or use `DefaultHttpDataFactory.setBaseDir(...)` to set the directory to something that is only readable by the current user.\n\n### References\n\n - [CWE-378: Creation of Temporary File With Insecure Permissions](https://cwe.mitre.org/data/definitions/378.html)\n - [CWE-379: Creation of Temporary File in Directory with Insecure Permissions](https://cwe.mitre.org/data/definitions/379.html)\n\n### Similar Vulnerabilities\n\nSimilar, but not the same.\n\n - JUnit 4 - https://github.com/junit-team/junit4/security/advisories/GHSA-269g-pwp5-87pp\n - Google Guava - https://github.com/google/guava/issues/4011\n - Apache Ant - https://nvd.nist.gov/vuln/detail/CVE-2020-1945\n - JetBrains Kotlin Compiler - https://nvd.nist.gov/vuln/detail/CVE-2020-15824\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [netty](https://github.com/netty/netty)\n* Email us [here](mailto:netty-security@googlegroups.com)\n\n### Original Report\n\n\u003e Hi Netty Security Team,\n\u003e \n\u003e I\u0027ve been working on some security research leveraging custom CodeQL queries to detect local information disclosure vulnerabilities in java applications. This was the result from running this query against the netty project:\n\u003e https://lgtm.com/query/7723301787255288599/\n\u003e \n\u003e Netty contains three local information disclosure vulnerabilities, so far as I can tell.\n\u003e \n\u003e One is here, where the private key for the certificate is written to a temporary file.\n\u003e \n\u003e https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/handler/src/main/java/io/netty/handler/ssl/util/SelfSignedCertificate.java#L316-L346\n\u003e \n\u003e One is here, where the certificate is written to a temporary file.\n\u003e \n\u003e https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/handler/src/main/java/io/netty/handler/ssl/util/SelfSignedCertificate.java#L348-L371\n\u003e \n\u003e The final one is here, where the \u0027AbstractDiskHttpData\u0027 creates a temporary file if the getBaseDirectory() method returns null. I believe that \u0027AbstractDiskHttpData\u0027 is used as a part of the file upload support? If this is the case, any files uploaded would be similarly vulnerable.\n\u003e \n\u003e https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/codec-http/src/main/java/io/netty/handler/codec/http/multipart/AbstractDiskHttpData.java#L91\n\u003e \n\u003e All of these vulnerabilities exist because `File.createTempFile(String, String)` will create a temporary file in the system temporary directory if the \u0027java.io.tmpdir\u0027 system property is not explicitly set. It is my understanding that when java creates a file, by default, and using this method, the permissions on that file utilize the umask. In a majority of cases, this means that the file that java creates has the permissions: `-rw-r--r--`, thus, any other local user on that system can read the contents of that file.\n\u003e \n\u003e Impacted OS:\n\u003e - Any OS where the system temporary directory is shared between multiple users. This is not the case for MacOS or Windows.\n\u003e \n\u003e Mitigation.\n\u003e \n\u003e Moving to the `Files` API instead will fix this vulnerability. \n\u003e https://docs.oracle.com/javase/8/docs/api/java/nio/file/Files.html#createTempFile-java.nio.file.Path-java.lang.String-java.lang.String-java.nio.file.attribute.FileAttribute...-\n\u003e \n\u003e This API will explicitly set the posix file permissions to something safe, by default.\n\u003e \n\u003e I recently disclosed a similar vulnerability in JUnit 4:\n\u003e https://github.com/junit-team/junit4/security/advisories/GHSA-269g-pwp5-87pp\n\u003e \n\u003e If you\u0027re also curious, this vulnerability in Jetty was also mine, also involving temporary directories, but is not the same vulnerability as in this case.\n\u003e https://github.com/eclipse/jetty.project/security/advisories/GHSA-g3wg-6mcf-8jj6\n\u003e \n\u003e I would appreciate it if we could perform disclosure of this vulnerability leveraging the GitHub security advisories feature here. GitHub has a nice credit system that I appreciate, plus the disclosures, as you can see from the sampling above, end up looking very nice.\n\u003e https://github.com/netty/netty/security/advisories\n\u003e \n\u003e This vulnerability disclosure follows Google\u0027s [90-day vulnerability disclosure policy](https://www.google.com/about/appsecurity/) (I\u0027m not an employee of Google, I just like their policy). Full disclosure will occur either at the end of the 90-day deadline or whenever a patch is made widely available, whichever occurs first.\n\u003e \n\u003e Cheers,\n\u003e Jonathan Leitschuh",
  "id": "GHSA-5mcr-gq6c-3hq2",
  "modified": "2022-04-19T15:19:08Z",
  "published": "2021-02-08T21:17:48Z",
  "references": [
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    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2021/02/msg00016.html"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20220210-0011"
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    {
      "type": "WEB",
      "url": "https://www.debian.org/security/2021/dsa-4885"
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    {
      "type": "WEB",
      "url": "https://www.oracle.com//security-alerts/cpujul2021.html"
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    {
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      "url": "https://www.oracle.com/security-alerts/cpuApr2021.html"
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      "url": "https://lists.apache.org/thread.html/r71dbb66747ff537640bb91eb0b2b24edef21ac07728097016f58b01f@%3Ccommits.kafka.apache.org%3E"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread.html/r743149dcc8db1de473e6bff0b3ddf10140a7357bc2add75f7d1fbb12@%3Cdev.zookeeper.apache.org%3E"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread.html/r790c2926efcd062067eb18fde2486527596d7275381cfaff2f7b3890@%3Cissues.bookkeeper.apache.org%3E"
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  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Local Information Disclosure Vulnerability in Netty on Unix-Like systems"
}
Mitigation
Requirements

Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible.

Mitigation
Implementation

Try to store sensitive tempfiles in a directory which is not world readable -- i.e., per-user directories.

Mitigation
Implementation

Avoid using vulnerable temp file functions.

No CAPEC attack patterns related to this CWE.

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