GSD-2021-29471

Vulnerability from gsd - Updated: 2023-12-13 01:23
Details
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.33.2 "Push rules" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.
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Aliases
CVE-2021-29471
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{
  "GSD": {
    "alias": "CVE-2021-29471",
    "description": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.33.2 \"Push rules\" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.",
    "id": "GSD-2021-29471",
    "references": [
      "https://www.suse.com/security/cve/CVE-2021-29471.html",
      "https://security.archlinux.org/CVE-2021-29471"
    ]
  },
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "aliases": [
        "CVE-2021-29471"
      ],
      "details": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.33.2 \"Push rules\" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.",
      "id": "GSD-2021-29471",
      "modified": "2023-12-13T01:23:36.940636Z",
      "schema_version": "1.4.0"
    }
  },
  "namespaces": {
    "cve.org": {
      "CVE_data_meta": {
        "ASSIGNER": "security-advisories@github.com",
        "ID": "CVE-2021-29471",
        "STATE": "PUBLIC",
        "TITLE": "Denial of service in Matrix Synapse"
      },
      "affects": {
        "vendor": {
          "vendor_data": [
            {
              "product": {
                "product_data": [
                  {
                    "product_name": "synapse",
                    "version": {
                      "version_data": [
                        {
                          "version_value": "\u003c 1.33.2"
                        }
                      ]
                    }
                  }
                ]
              },
              "vendor_name": "matrix-org"
            }
          ]
        }
      },
      "data_format": "MITRE",
      "data_type": "CVE",
      "data_version": "4.0",
      "description": {
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          {
            "lang": "eng",
            "value": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.33.2 \"Push rules\" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy."
          }
        ]
      },
      "impact": {
        "cvss": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "version": "3.1"
        }
      },
      "problemtype": {
        "problemtype_data": [
          {
            "description": [
              {
                "lang": "eng",
                "value": "CWE-400: Uncontrolled Resource Consumption"
              }
            ]
          }
        ]
      },
      "references": {
        "reference_data": [
          {
            "name": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85",
            "refsource": "CONFIRM",
            "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85"
          },
          {
            "name": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c",
            "refsource": "MISC",
            "url": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c"
          },
          {
            "name": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2",
            "refsource": "MISC",
            "url": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2"
          },
          {
            "name": "FEDORA-2021-a627cfd31e",
            "refsource": "FEDORA",
            "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"
          }
        ]
      },
      "source": {
        "advisory": "GHSA-x345-32rc-8h85",
        "discovery": "UNKNOWN"
      }
    },
    "gitlab.com": {
      "advisories": [
        {
          "affected_range": "\u003c1.33.2",
          "affected_versions": "All versions before 1.33.2",
          "cvss_v2": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "cvss_v3": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "cwe_ids": [
            "CWE-1035",
            "CWE-331",
            "CWE-937"
          ],
          "date": "2022-04-05",
          "description": "Synapse is a Matrix reference homeserver written in python. Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse `Push rules` can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.",
          "fixed_versions": [
            "1.33.2"
          ],
          "identifier": "CVE-2021-29471",
          "identifiers": [
            "CVE-2021-29471",
            "GHSA-x345-32rc-8h85"
          ],
          "not_impacted": "All versions starting from 1.33.2",
          "package_slug": "pypi/matrix-synapse",
          "pubdate": "2021-05-11",
          "solution": "Upgrade to version 1.33.2 or above.",
          "title": "Uncontrolled Resource Consumption",
          "urls": [
            "https://nvd.nist.gov/vuln/detail/CVE-2021-29471"
          ],
          "uuid": "a6208740-0787-4b4b-a662-547fd71d5f3a"
        }
      ]
    },
    "nvd.nist.gov": {
      "configurations": {
        "CVE_data_version": "4.0",
        "nodes": [
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*",
                "cpe_name": [],
                "versionEndExcluding": "1.33.2",
                "vulnerable": true
              }
            ],
            "operator": "OR"
          },
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              }
            ],
            "operator": "OR"
          }
        ]
      },
      "cve": {
        "CVE_data_meta": {
          "ASSIGNER": "security-advisories@github.com",
          "ID": "CVE-2021-29471"
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "en",
              "value": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.33.2 \"Push rules\" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "en",
                  "value": "CWE-331"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2",
              "refsource": "MISC",
              "tags": [
                "Release Notes",
                "Third Party Advisory"
              ],
              "url": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2"
            },
            {
              "name": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85",
              "refsource": "CONFIRM",
              "tags": [
                "Patch",
                "Third Party Advisory"
              ],
              "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85"
            },
            {
              "name": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c",
              "refsource": "MISC",
              "tags": [
                "Patch",
                "Third Party Advisory"
              ],
              "url": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c"
            },
            {
              "name": "FEDORA-2021-a627cfd31e",
              "refsource": "FEDORA",
              "tags": [
                "Mailing List",
                "Third Party Advisory"
              ],
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"
            }
          ]
        }
      },
      "impact": {
        "baseMetricV2": {
          "acInsufInfo": false,
          "cvssV2": {
            "accessComplexity": "LOW",
            "accessVector": "NETWORK",
            "authentication": "NONE",
            "availabilityImpact": "PARTIAL",
            "baseScore": 5.0,
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
            "version": "2.0"
          },
          "exploitabilityScore": 10.0,
          "impactScore": 2.9,
          "obtainAllPrivilege": false,
          "obtainOtherPrivilege": false,
          "obtainUserPrivilege": false,
          "severity": "MEDIUM",
          "userInteractionRequired": false
        },
        "baseMetricV3": {
          "cvssV3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
            "version": "3.1"
          },
          "exploitabilityScore": 3.9,
          "impactScore": 1.4
        }
      },
      "lastModifiedDate": "2022-04-05T18:06Z",
      "publishedDate": "2021-05-11T15:15Z"
    }
  }
}



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