Vulnerability-Lookup

GHSA-86C2-4X57-WC8G

Vulnerability from github – Published: 2025-01-14 19:40 – Updated: 2025-01-14 21:59

Summary

Git Credential Manager carriage-return character in remote URL allows malicious repository to leak credentials

Details

Description

The Git credential protocol is text-based over standard input/output, and consists of a series of lines of key-value pairs in the format key=value. Git's documentation restricts the use of the NUL (\0) character and newlines to form part of the keys[^1] or values.

When Git reads from standard input, it considers both LF and CRLF[^2] as newline characters for the credential protocol by virtue of calling strbuf_getline that calls to strbuf_getdelim_strip_crlf. Git also validates that a newline is not present in the value by checking for the presence of the line-feed character (LF, \n), and errors if this is the case. This captures both LF and CRLF-type newlines.

Git Credential Manager uses the .NET standard library StreamReader class to read the standard input stream line-by-line and parse the key=value credential protocol format. The implementation of the ReadLineAsync method considers LF, CRLF, and CR as valid line endings. This is means that .NET considers a single CR as a valid newline character, whereas Git does not.

This mismatch of newline treatment between Git and GCM means that an attacker can craft a malicious remote URL such as:

https://\rhost=targethost@badhost

..which will be interpreted by Git as:

protocol=https
host=badhost
username=\rhost=targethost

This will instead be parsed by GCM as if the following has been passed by Git:

protocol=https
host=badhost
username=
host=targethost

This results in the host field being resolved to the targethost value. GCM will then return a credential for targethost to Git, which will then send this credential to the badhost host.

Impact

When a user clones or otherwise interacts[^3] with a malicious repository that requires authentication, the attacker can capture credentials for another Git remote. The attack is also heightened when cloning from repositories with submodules when using the --recursive clone option as the user is not able to inspect the submodule remote URLs beforehand.

Patches

https://github.com/git-ecosystem/git-credential-manager/compare/749e287571c78a2b61f926ccce6a707050871ab8...99e2f7f60e7364fe807e7925f361a81f3c47bd1b

Workarounds

Only interacting with trusted remote repositories, and do not clone with --recursive to allow inspection of any submodule URLs before cloning those submodules.

Fixed versions

This issue is fixed as of version 2.6.1.

[^1]: The = character is also forbidden to form part of the key. [^2]: Carriage-return character (CR, \r), followed by a line-feed character. [^3]: Any remote operation such as fetch, ls-remote, etc.

Severity

7.4 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

Show details on source website

JSON

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.6.0"
      },
      "package": {
        "ecosystem": "NuGet",
        "name": "git-credential-manager"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.6.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-50338"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200",
      "CWE-436"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-01-14T19:40:54Z",
    "nvd_published_at": "2025-01-14T19:15:31Z",
    "severity": "HIGH"
  },
  "details": "### Description\nThe [Git credential protocol](https://git-scm.com/docs/git-credential#IOFMT) is text-based over standard input/output, and consists of a series of lines of key-value pairs in the format `key=value`. Git\u0027s documentation restricts the use of the NUL (`\\0`) character and newlines to form part of the keys[^1] or values.\n\nWhen Git reads from standard input, it considers both LF and CRLF[^2] as newline characters for the credential protocol by virtue of [calling `strbuf_getline`](https://github.com/git/git/blob/6a11438f43469f3815f2f0fc997bd45792ff04c0/credential.c#L311) that calls to `strbuf_getdelim_strip_crlf`. Git also validates that a newline is not present in the value by checking for the presence of the line-feed character (LF, `\\n`), and errors if this is the case. This captures both LF and CRLF-type newlines.\n\nGit Credential Manager uses the .NET standard library [`StreamReader`](https://learn.microsoft.com/en-us/dotnet/api/system.io.streamreader?view=net-8.0) class to [read the standard input stream line-by-line](https://github.com/git-ecosystem/git-credential-manager/blob/ae009e11a0fbef804ad9f78816d84a0bc7e052fe/src/shared/Core/StreamExtensions.cs#L138-L141) and parse the `key=value` credential protocol format. The [implementation of the `ReadLineAsync` method](https://github.com/dotnet/runtime/blob/e476b43b5cb42eb44ce23b1c7b793aa361624cf6/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs#L926) considers LF, CRLF, and CR as valid line endings. This is means that .NET considers a single CR as a valid newline character, whereas Git does not.\n\nThis mismatch of newline treatment between Git and GCM means that an attacker can craft a malicious remote URL such as:\n\n```\nhttps://\\rhost=targethost@badhost\n```\n\n..which will be interpreted by Git as:\n\n```\nprotocol=https\nhost=badhost\nusername=\\rhost=targethost\n```\n\nThis will instead be parsed by GCM as if the following has been passed by Git:\n\n```\nprotocol=https\nhost=badhost\nusername=\nhost=targethost\n```\n\nThis results in the `host` field being resolved to the `targethost` value. GCM will then return a credential for `targethost` to Git, which will then send this credential to the `badhost` host.\n\n### Impact\nWhen a user clones or otherwise interacts[^3] with a malicious repository that requires authentication, the attacker can capture credentials for another Git remote. The attack is also heightened when cloning from repositories with submodules when using the `--recursive` clone option as the user is not able to inspect the submodule remote URLs beforehand.\n\n### Patches\nhttps://github.com/git-ecosystem/git-credential-manager/compare/749e287571c78a2b61f926ccce6a707050871ab8...99e2f7f60e7364fe807e7925f361a81f3c47bd1b\n\n### Workarounds\nOnly interacting with trusted remote repositories, and do not clone with `--recursive` to allow inspection of any submodule URLs before cloning those submodules.\n\n### Fixed versions\nThis issue is fixed as of [version 2.6.1](https://github.com/git-ecosystem/git-credential-manager/releases/tag/v2.6.1).\n\n[^1]: The `=` character is also forbidden to form part of the key.\n[^2]: Carriage-return character (CR, `\\r`), followed by a line-feed character.\n[^3]: Any remote operation such as `fetch`, `ls-remote`, etc.",
  "id": "GHSA-86c2-4x57-wc8g",
  "modified": "2025-01-14T21:59:51Z",
  "published": "2025-01-14T19:40:54Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/git-ecosystem/git-credential-manager/security/advisories/GHSA-86c2-4x57-wc8g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-50338"
    },
    {
      "type": "WEB",
      "url": "https://git-scm.com/docs/git-credential#IOFMT"
    },
    {
      "type": "WEB",
      "url": "https://github.com/dotnet/runtime/blob/e476b43b5cb42eb44ce23b1c7b793aa361624cf6/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs#L926"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/git-ecosystem/git-credential-manager"
    },
    {
      "type": "WEB",
      "url": "https://github.com/git-ecosystem/git-credential-manager/blob/ae009e11a0fbef804ad9f78816d84a0bc7e052fe/src/shared/Core/StreamExtensions.cs#L138-L141"
    },
    {
      "type": "WEB",
      "url": "https://github.com/git-ecosystem/git-credential-manager/compare/749e287571c78a2b61f926ccce6a707050871ab8...99e2f7f60e7364fe807e7925f361a81f3c47bd1b"
    },
    {
      "type": "WEB",
      "url": "https://github.com/git-ecosystem/git-credential-manager/releases/tag/v2.6.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/git/git/blob/6a11438f43469f3815f2f0fc997bd45792ff04c0/credential.c#L311"
    },
    {
      "type": "WEB",
      "url": "https://learn.microsoft.com/en-us/dotnet/api/system.io.streamreader?view=net-8.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Git Credential Manager carriage-return character in remote URL allows malicious repository to leak credentials"
}

CVE-2024-50338 (GCVE-0-2024-50338)

Vulnerability from cvelistv5 – Published: 2025-01-14 18:11 – Updated: 2025-01-14 18:35

Title

Carriage-return character in remote URL allows malicious repository to leak credentials in Git Credential Manager

Summary

Git Credential Manager (GCM) is a secure Git credential helper built on .NET that runs on Windows, macOS, and Linux. The Git credential protocol is text-based over standard input/output, and consists of a series of lines of key-value pairs in the format `key=value`. Git's documentation restricts the use of the NUL (`\0`) character and newlines to form part of the keys or values. When Git reads from standard input, it considers both LF and CRLF as newline characters for the credential protocol by virtue of calling `strbuf_getline` that calls to `strbuf_getdelim_strip_crlf`. Git also validates that a newline is not present in the value by checking for the presence of the line-feed character (LF, `\n`), and errors if this is the case. This captures both LF and CRLF-type newlines. Git Credential Manager uses the .NET standard library `StreamReader` class to read the standard input stream line-by-line and parse the `key=value` credential protocol format. The implementation of the `ReadLineAsync` method considers LF, CRLF, and CR as valid line endings. This is means that .NET considers a single CR as a valid newline character, whereas Git does not. This mismatch of newline treatment between Git and GCM means that an attacker can craft a malicious remote URL. When a user clones or otherwise interacts with a malicious repository that requires authentication, the attacker can capture credentials for another Git remote. The attack is also heightened when cloning from repositories with submodules when using the `--recursive` clone option as the user is not able to inspect the submodule remote URLs beforehand. This issue has been patched in version 2.6.1 and all users are advised to upgrade. Users unable to upgrade should only interact with trusted remote repositories, and not clone with `--recursive` to allow inspection of any submodule URLs before cloning those submodules.

Severity

7.4 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-01-14 18:35 UTC

CWE

CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor

Assigner

GitHub_M mitre root

References

8 references

URL	Tags
https://github.com/git-ecosystem/git-credential-m…	x_refsource_CONFIRM
https://git-scm.com/docs/git-credential#IOFMT	x_refsource_MISC
https://github.com/dotnet/runtime/blob/e476b43b5c…	x_refsource_MISC
https://github.com/git-ecosystem/git-credential-m…	x_refsource_MISC
https://github.com/git-ecosystem/git-credential-m…	x_refsource_MISC
https://github.com/git-ecosystem/git-credential-m…	x_refsource_MISC
https://github.com/git/git/blob/6a11438f43469f381…	x_refsource_MISC
https://learn.microsoft.com/en-us/dotnet/api/syst…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
git-ecosystem	git-credential-manager	Affected: < 2.6.1

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2024-50338",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-01-14T18:35:22.661757Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-01-14T18:35:33.115Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "git-credential-manager",
          "vendor": "git-ecosystem",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.6.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Git Credential Manager (GCM) is a secure Git credential helper built on .NET that runs on Windows, macOS, and Linux. The Git credential protocol is text-based over standard input/output, and consists of a series of lines of key-value pairs in the format `key=value`. Git\u0027s documentation restricts the use of the NUL (`\\0`) character and newlines to form part of the keys or values. When Git reads from standard input, it considers both LF and CRLF as newline characters for the credential protocol by virtue of calling `strbuf_getline` that calls to `strbuf_getdelim_strip_crlf`. Git also validates that a newline is not present in the value by checking for the presence of the line-feed character (LF, `\\n`), and errors if this is the case. This captures both LF and CRLF-type newlines. Git Credential Manager uses the .NET standard library `StreamReader` class to read the standard input stream line-by-line and parse the `key=value` credential protocol format. The implementation of the `ReadLineAsync` method considers LF, CRLF, and CR as valid line endings. This is means that .NET considers a single CR as a valid newline character, whereas Git does not. This mismatch of newline treatment between Git and GCM means that an attacker can craft a malicious remote URL. When a user clones or otherwise interacts with a malicious repository that requires authentication, the attacker can capture credentials for another Git remote. The attack is also heightened when cloning from repositories with submodules when using the `--recursive` clone option as the user is not able to inspect the submodule remote URLs beforehand. This issue has been patched in version 2.6.1 and all users are advised to upgrade. Users unable to upgrade should only interact with trusted remote repositories, and not clone with `--recursive` to allow inspection of any submodule URLs before cloning those submodules."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.4,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-200",
              "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-01-14T18:11:23.188Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/git-ecosystem/git-credential-manager/security/advisories/GHSA-86c2-4x57-wc8g",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/git-ecosystem/git-credential-manager/security/advisories/GHSA-86c2-4x57-wc8g"
        },
        {
          "name": "https://git-scm.com/docs/git-credential#IOFMT",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://git-scm.com/docs/git-credential#IOFMT"
        },
        {
          "name": "https://github.com/dotnet/runtime/blob/e476b43b5cb42eb44ce23b1c7b793aa361624cf6/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs#L926",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/dotnet/runtime/blob/e476b43b5cb42eb44ce23b1c7b793aa361624cf6/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs#L926"
        },
        {
          "name": "https://github.com/git-ecosystem/git-credential-manager/blob/ae009e11a0fbef804ad9f78816d84a0bc7e052fe/src/shared/Core/StreamExtensions.cs#L138-L141",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/git-ecosystem/git-credential-manager/blob/ae009e11a0fbef804ad9f78816d84a0bc7e052fe/src/shared/Core/StreamExtensions.cs#L138-L141"
        },
        {
          "name": "https://github.com/git-ecosystem/git-credential-manager/compare/749e287571c78a2b61f926ccce6a707050871ab8...99e2f7f60e7364fe807e7925f361a81f3c47bd1b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/git-ecosystem/git-credential-manager/compare/749e287571c78a2b61f926ccce6a707050871ab8...99e2f7f60e7364fe807e7925f361a81f3c47bd1b"
        },
        {
          "name": "https://github.com/git-ecosystem/git-credential-manager/releases/tag/v2.6.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/git-ecosystem/git-credential-manager/releases/tag/v2.6.1"
        },
        {
          "name": "https://github.com/git/git/blob/6a11438f43469f3815f2f0fc997bd45792ff04c0/credential.c#L311",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/git/git/blob/6a11438f43469f3815f2f0fc997bd45792ff04c0/credential.c#L311"
        },
        {
          "name": "https://learn.microsoft.com/en-us/dotnet/api/system.io.streamreader?view=net-8.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://learn.microsoft.com/en-us/dotnet/api/system.io.streamreader?view=net-8.0"
        }
      ],
      "source": {
        "advisory": "GHSA-86c2-4x57-wc8g",
        "discovery": "UNKNOWN"
      },
      "title": "Carriage-return character in remote URL allows malicious repository to leak credentials in Git Credential Manager"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2024-50338",
    "datePublished": "2025-01-14T18:11:23.188Z",
    "dateReserved": "2024-10-22T17:54:40.954Z",
    "dateUpdated": "2025-01-14T18:35:33.115Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.