Vulnerability-Lookup

GHSA-M298-FH5C-JC66

Vulnerability from github – Published: 2021-05-04 17:42 – Updated: 2026-07-21 13:42

Summary

Object injection in PHPMailer/PHPMailer

Details

Impact

This is a reintroduction of an earlier issue (CVE-2018-19296) by an unrelated bug fix in PHPMailer 6.1.8. An external file may be unexpectedly executable if it is used as a path to an attachment file via PHP's support for .phar files. Exploitation requires that an attacker is able to provide an unfiltered path to a file to attach, or to trick calling code into generating one. See this article for more info.

Patches

This issue was patched in the PHPMailer 6.4.1 release. This release also implements stricter filtering for attachment paths; paths that look like any kind of URL are rejected.

Workarounds

Validate paths to loaded files using the same pattern as used in isPermittedPath() before using them in any PHP file function, such as file_exists. This method can't be used directly because it is protected, but you can implement the same thing in calling code. Note that this should be applied to all user-supplied paths passed into such functions; it's not a problem specific to PHPMailer.

Credit

This issue was found by Fariskhi Vidyan, reported and managed via Tidelift.

Severity

9.8 (Critical)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "phpmailer/phpmailer"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.1.8"
            },
            {
              "fixed": "6.4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-36326"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502",
      "CWE-641"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-04-30T19:41:24Z",
    "nvd_published_at": "2021-04-28T03:15:00Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\nThis is a reintroduction of an earlier issue (CVE-2018-19296) by an unrelated bug fix in PHPMailer 6.1.8.  An external file may be unexpectedly executable if it is used as a path to an attachment file via PHP\u0027s support for `.phar` files. Exploitation requires that an attacker is able to provide an unfiltered path to a file to attach, or to trick calling code into generating one. See [this article](https://knasmueller.net/5-answers-about-php-phar-exploitation) for more info.\n\n### Patches\nThis issue was patched in the PHPMailer 6.4.1 release. This release also implements stricter filtering for attachment paths; paths that look like *any* kind of URL are rejected.\n\n### Workarounds\nValidate paths to loaded files using the same pattern as used in [`isPermittedPath()`](https://github.com/PHPMailer/PHPMailer/blob/master/src/PHPMailer.php#L1815) before using them in *any* PHP file function, such as `file_exists`. This method can\u0027t be used directly because it is protected, but you can implement the same thing in calling code. Note that this should be applied to *all* user-supplied paths passed into such functions; it\u0027s not a problem specific to PHPMailer.\n\n### Credit\nThis issue was found by [Fariskhi Vidyan](https://github.com/farisv), reported and managed via Tidelift.",
  "id": "GHSA-m298-fh5c-jc66",
  "modified": "2026-07-21T13:42:46Z",
  "published": "2021-05-04T17:42:13Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/PHPMailer/PHPMailer/security/advisories/GHSA-m298-fh5c-jc66"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-36326"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PHPMailer/PHPMailer/commit/e2e07a355ee8ff36aba21d0242c5950c56e4c6f9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/phpmailer/phpmailer/CVE-2020-36326.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/PHPMailer/PHPMailer"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PHPMailer/PHPMailer/releases/tag/v6.4.1"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3B5WDPGUFNPG4NAZ6G4BZX43BKLAVA5B"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KPU66INRFY5BQ3ESVPRUXJR4DXQAFJVT"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Object injection in PHPMailer/PHPMailer"
}

CVE-2020-36326 (GCVE-0-2020-36326)

Vulnerability from cvelistv5 – Published: 2021-04-28 02:21 – Updated: 2024-08-04 17:23

Summary

PHPMailer 6.1.8 through 6.4.0 allows object injection through Phar Deserialization via addAttachment with a UNC pathname. NOTE: this is similar to CVE-2018-19296, but arose because 6.1.8 fixed a functionality problem in which UNC pathnames were always considered unreadable by PHPMailer, even in safe contexts. As an unintended side effect, this fix eliminated the code that blocked addAttachment exploitation.

Severity

No CVSS data available.

CWE

Assigner

mitre CNA under the mitre root

CNA scorecard E 29/100 over 2166 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/PHPMailer/PHPMailer/commit/e2e…	x_refsource_MISC
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA

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JSON

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{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T17:23:10.518Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/PHPMailer/PHPMailer/commit/e2e07a355ee8ff36aba21d0242c5950c56e4c6f9"
          },
          {
            "name": "FEDORA-2021-b21bbfa198",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KPU66INRFY5BQ3ESVPRUXJR4DXQAFJVT/"
          },
          {
            "name": "FEDORA-2021-ecf4fed550",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3B5WDPGUFNPG4NAZ6G4BZX43BKLAVA5B/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "PHPMailer 6.1.8 through 6.4.0 allows object injection through Phar Deserialization via addAttachment with a UNC pathname. NOTE: this is similar to CVE-2018-19296, but arose because 6.1.8 fixed a functionality problem in which UNC pathnames were always considered unreadable by PHPMailer, even in safe contexts. As an unintended side effect, this fix eliminated the code that blocked addAttachment exploitation."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-05-12T17:06:28.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/PHPMailer/PHPMailer/commit/e2e07a355ee8ff36aba21d0242c5950c56e4c6f9"
        },
        {
          "name": "FEDORA-2021-b21bbfa198",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KPU66INRFY5BQ3ESVPRUXJR4DXQAFJVT/"
        },
        {
          "name": "FEDORA-2021-ecf4fed550",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3B5WDPGUFNPG4NAZ6G4BZX43BKLAVA5B/"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2020-36326",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "n/a",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "n/a"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "PHPMailer 6.1.8 through 6.4.0 allows object injection through Phar Deserialization via addAttachment with a UNC pathname. NOTE: this is similar to CVE-2018-19296, but arose because 6.1.8 fixed a functionality problem in which UNC pathnames were always considered unreadable by PHPMailer, even in safe contexts. As an unintended side effect, this fix eliminated the code that blocked addAttachment exploitation."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "n/a"
                }
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        "references": {
          "reference_data": [
            {
              "name": "https://github.com/PHPMailer/PHPMailer/commit/e2e07a355ee8ff36aba21d0242c5950c56e4c6f9",
              "refsource": "MISC",
              "url": "https://github.com/PHPMailer/PHPMailer/commit/e2e07a355ee8ff36aba21d0242c5950c56e4c6f9"
            },
            {
              "name": "FEDORA-2021-b21bbfa198",
              "refsource": "FEDORA",
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KPU66INRFY5BQ3ESVPRUXJR4DXQAFJVT/"
            },
            {
              "name": "FEDORA-2021-ecf4fed550",
              "refsource": "FEDORA",
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3B5WDPGUFNPG4NAZ6G4BZX43BKLAVA5B/"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2020-36326",
    "datePublished": "2021-04-28T02:21:53.000Z",
    "dateReserved": "2021-04-28T00:00:00.000Z",
    "dateUpdated": "2024-08-04T17:23:10.518Z",
    "state": "PUBLISHED"
  },
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  "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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.

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