FKIE_CVE-2021-26691

Vulnerability from fkie_nvd - Published: 2021-06-10 07:15 - Updated: 2026-06-17 03:43
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow
References
security@apache.orghttp://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
security@apache.orghttp://www.openwall.com/lists/oss-security/2021/06/10/7Mailing List, Third Party Advisory
security@apache.orghttps://lists.apache.org/thread.html/r50cae1b71f1e7421069036b213c26da7d8f47dd59874e3bd956959fe%40%3Cannounce.httpd.apache.org%3E
security@apache.orghttps://lists.apache.org/thread.html/r7f2b70b621651548f4b6f027552f1dd91705d7111bb5d15cda0a68dd%40%3Cdev.httpd.apache.org%3E
security@apache.orghttps://lists.apache.org/thread.html/re026d3da9d7824bd93b9f871c0fdda978d960c7e62d8c43cba8d0bf3%40%3Ccvs.httpd.apache.org%3EMailing List, Release Notes, Vendor Advisory
security@apache.orghttps://lists.debian.org/debian-lts-announce/2021/07/msg00006.htmlMailing List, Third Party Advisory
security@apache.orghttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
security@apache.orghttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
security@apache.orghttps://security.gentoo.org/glsa/202107-38Third Party Advisory
security@apache.orghttps://security.netapp.com/advisory/ntap-20210702-0001/Third Party Advisory
security@apache.orghttps://www.debian.org/security/2021/dsa-4937Mailing List, Third Party Advisory
security@apache.orghttps://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
security@apache.orghttps://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108http://httpd.apache.org/security/vulnerabilities_24.htmlVendor Advisory
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/06/10/7Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.apache.org/thread.html/r50cae1b71f1e7421069036b213c26da7d8f47dd59874e3bd956959fe%40%3Cannounce.httpd.apache.org%3E
af854a3a-2127-422b-91ae-364da2661108https://lists.apache.org/thread.html/r7f2b70b621651548f4b6f027552f1dd91705d7111bb5d15cda0a68dd%40%3Cdev.httpd.apache.org%3E
af854a3a-2127-422b-91ae-364da2661108https://lists.apache.org/thread.html/re026d3da9d7824bd93b9f871c0fdda978d960c7e62d8c43cba8d0bf3%40%3Ccvs.httpd.apache.org%3EMailing List, Release Notes, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2021/07/msg00006.htmlMailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202107-38Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://security.netapp.com/advisory/ntap-20210702-0001/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.debian.org/security/2021/dsa-4937Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
Impacted products
Vendor Product Version
apache http_server *
debian debian_linux 9.0
debian debian_linux 10.0
fedoraproject fedora 34
fedoraproject fedora 35
oracle enterprise_manager_ops_center 12.4.0.0
oracle instantis_enterprisetrack 17.1
oracle instantis_enterprisetrack 17.2
oracle instantis_enterprisetrack 17.3
oracle secure_backup *
oracle zfs_storage_appliance_kit 8.8
netapp cloud_backup -
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Apache HTTP Server",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "status": "affected",
              "version": "2.4.46"
            },
            {
              "status": "affected",
              "version": "2.4.43"
            },
            {
              "status": "affected",
              "version": "2.4.41"
            },
            {
              "status": "affected",
              "version": "2.4.39"
            },
            {
              "status": "affected",
              "version": "2.4.38"
            },
            {
              "status": "affected",
              "version": "2.4.37"
            },
            {
              "status": "affected",
              "version": "2.4.35"
            },
            {
              "status": "affected",
              "version": "2.4.34"
            },
            {
              "status": "affected",
              "version": "2.4.33"
            },
            {
              "status": "affected",
              "version": "2.4.29"
            },
            {
              "status": "affected",
              "version": "2.4.28"
            },
            {
              "status": "affected",
              "version": "2.4.27"
            },
            {
              "status": "affected",
              "version": "2.4.26"
            },
            {
              "status": "affected",
              "version": "2.4.25"
            },
            {
              "status": "affected",
              "version": "2.4.23"
            },
            {
              "status": "affected",
              "version": "2.4.20"
            },
            {
              "status": "affected",
              "version": "2.4.18"
            },
            {
              "status": "affected",
              "version": "2.4.17"
            },
            {
              "status": "affected",
              "version": "2.4.16"
            },
            {
              "status": "affected",
              "version": "2.4.12"
            },
            {
              "status": "affected",
              "version": "2.4.10"
            },
            {
              "status": "affected",
              "version": "2.4.9"
            },
            {
              "status": "affected",
              "version": "2.4.7"
            },
            {
              "status": "affected",
              "version": "2.4.6"
            },
            {
              "status": "affected",
              "version": "2.4.4"
            },
            {
              "status": "affected",
              "version": "2.4.3"
            },
            {
              "status": "affected",
              "version": "2.4.2"
            },
            {
              "status": "affected",
              "version": "2.4.1"
            },
            {
              "status": "affected",
              "version": "2.4.0"
            }
          ]
        }
      ],
      "source": "security@apache.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "8375A8C8-38EB-4F32-97FD-0841D57C1971",
              "versionEndIncluding": "2.4.46",
              "versionStartIncluding": "2.4.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
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      "nodes": [
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          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
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              "criteria": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
              "matchCriteriaId": "A930E247-0B43-43CB-98FF-6CE7B8189835",
              "vulnerable": true
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              "matchCriteriaId": "80E516C0-98A4-4ADE-B69F-66A772E2BAAA",
              "vulnerable": true
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              "vulnerable": true
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              "matchCriteriaId": "B9C9BC66-FA5F-4774-9BDA-7AB88E2839C4",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*",
              "matchCriteriaId": "7F69B9A5-F21B-4904-9F27-95C0F7A628E3",
              "vulnerable": true
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            {
              "criteria": "cpe:2.3:a:oracle:secure_backup:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C01E8B82-71C7-4A4A-A70A-7B147524AB4A",
              "versionEndExcluding": "18.1.0.1.0",
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            },
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              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow"
    },
    {
      "lang": "es",
      "value": "Apache HTTP Server versiones 2.4.0 a 2.4.46 , un par\u00e1metro SessionHeader especialmente dise\u00f1ado enviado por un servidor de origen podr\u00eda causar un desbordamiento de pila"
    }
  ],
  "id": "CVE-2021-26691",
  "lastModified": "2026-06-17T03:43:38.857",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 7.5,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 6.4,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-06-10T07:15:07.580",
  "references": [
    {
      "source": "security@apache.org",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "http://httpd.apache.org/security/vulnerabilities_24.html"
    },
    {
      "source": "security@apache.org",
      "tags": [
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    },
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      ],
      "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
    }
  ],
  "sourceIdentifier": "security@apache.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-122"
        }
      ],
      "source": "security@apache.org",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.
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  • 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.



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