« Back to list

CVE-2021-31548

Status: ModifiedMedium (6.5)—

An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. A MediaWiki user who is partially blocked or was unsuccessfully blocked could bypass AbuseFilter and have their edits completed.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Mediawiki — Mediawiki

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2021-31548",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 4,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:S/C:N/I:P/A:N",
          "authentication": "SINGLE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.5,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2021-04-22T03:15:08.033",
  "references": [
    {
      "url": "https://gerrit.wikimedia.org/r/q/Ifac795125927d584a31d95e1b4c4241eef860fa1",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://phabricator.wikimedia.org/T272333",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://gerrit.wikimedia.org/r/q/Ifac795125927d584a31d95e1b4c4241eef860fa1",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://phabricator.wikimedia.org/T272333",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. A MediaWiki user who is partially blocked or was unsuccessfully blocked could bypass AbuseFilter and have their edits completed."
    },
    {
      "lang": "es",
      "value": "Se detectó un problema en la extensión AbuseFilter para MediaWiki versiones hasta 1.35.2. Un usuario de MediaWiki que está parcialmente bloqueado o que ha sido bloqueado sin éxito podía omitir AbuseFilter y completar sus ediciones"
    }
  ],
  "lastModified": "2026-06-17T03:51:59.197",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4067807D-769C-485F-A7E3-EE96885BDCE7",
              "versionEndIncluding": "1.35.2"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}