{
  "id": "CVE-2021-41773",
  "url": "https://spydr.io/cve/CVE-2021-41773",
  "published": "2021-10-05T09:15:07.593Z",
  "modified": "2026-06-17T04:08:53.933Z",
  "score": 9.8,
  "severity": "critical",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "score_source": "NVD",
  "epss": 0.99992,
  "epss_percentile": 0.99986,
  "exploited": true,
  "kev": {
    "added": "2021-11-03",
    "due": "2021-11-17",
    "action": "Apply updates per vendor instructions.",
    "ransomware": "Known",
    "name": "Apache HTTP Server Path Traversal Vulnerability",
    "notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-41773"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "Apache Software Foundation"
  ],
  "products": [
    "Apache Software Foundation Apache HTTP Server"
  ],
  "cwes": [
    "CWE-22"
  ],
  "description": "A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration \"require all denied\", these requests can succeed. If CGI scripts are also enabled for these aliased pathes, this could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 was found to be incomplete, see CVE-2021-42013.",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 9.8,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal-Remote-Code-Execution.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2021/10/05/2",
      "tags": [
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      ]
    },
    {
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      "tags": [
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    {
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      "url": "http://www.openwall.com/lists/oss-security/2021/10/15/3",
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    },
    {
      "url": "https://httpd.apache.org/security/vulnerabilities_24.html",
      "tags": [
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        "Vendor Advisory"
      ]
    },
    {
      "url": "https://lists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb23392fc68264c72cb3%40%3Ccvs.httpd.apache.org%3E",
      "tags": [
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    {
      "url": "https://lists.apache.org/thread.html/r6abf5f2ba6f1aa8b1030f95367aaf17660c4e4c78cb2338aee18982f%40%3Cusers.httpd.apache.org%3E",
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      "url": "https://lists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%40%3Cusers.httpd.apache.org%3E",
      "tags": [
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    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RMIIEFINL6FUIOPD2A3M5XC6DH45Y3CC/",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WS5RVHOIIRECG65ZBTZY7IEJVWQSQPG3/",
      "tags": [
        "Release Notes"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-41773",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}