Vulnerability-Lookup

GSD-2021-31618

Vulnerability from gsd - Updated: 2023-12-13 01:23

Details

Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of these restrictions and HTTP response is sent to the client with a status code indicating why the request was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the offending header was the very first one received or appeared in a a footer. This led to a NULL pointer dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited to DoS the server. This issue affected mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never released.

Aliases

CVE-2021-31618

Aliases

CVE-2021-31618

JSON

To clipboard

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            "accessVector": "NETWORK",
            "authentication": "NONE",
            "availabilityImpact": "PARTIAL",
            "baseScore": 5.0,
            "confidentialityImpact": "NONE",
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            "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
            "version": "2.0"
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            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "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:H",
            "version": "3.1"
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      },
      "lastModifiedDate": "2021-12-10T17:05Z",
      "publishedDate": "2021-06-15T09:15Z"
    }
  }
}

CVE-2021-31618 (GCVE-0-2021-31618)

Vulnerability from cvelistv5 – Published: 2021-06-15 00:00 – Updated: 2024-08-03 23:03

Title

NULL pointer dereference on specially crafted HTTP/2 request

Summary

Severity

No CVSS data available.

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-05-20 16:18 UTC

CWE

CWE-476 - NULL Pointer Dereference

Assigner

apache mitre root

References

13 references

URL	Tags
http://httpd.apache.org/security/vulnerabilities_…
http://www.openwall.com/lists/oss-security/2021/06/10/9	mailing-list
https://seclists.org/oss-sec/2021/q2/206
https://lists.apache.org/thread.html/r14b66ef0f4f…	mailing-list
https://lists.apache.org/thread.html/r783b6558abf…	mailing-list
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisory
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisory
https://lists.debian.org/debian-lts-announce/2021…	mailing-list
https://www.debian.org/security/2021/dsa-4937	vendor-advisory
https://security.gentoo.org/glsa/202107-38	vendor-advisory
https://www.oracle.com/security-alerts/cpuoct2021.html
https://security.netapp.com/advisory/ntap-2021072…
http://www.openwall.com/lists/oss-security/2024/03/13/2	mailing-list

Impacted products

1 product

Vendor	Product	Version
Apache Software Foundation	Apache HTTP Server	Affected: 2.4.47

Credits

Apache HTTP server would like to thank LI ZHI XIN from NSFocus for reporting this.

Show details on NVD website

JSON

To clipboard

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            "url": "https://security.gentoo.org/glsa/202107-38"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210727-0008/"
          },
          {
            "name": "[oss-security] 20240313 Re: CVE-2021-31618: Apache httpd: NULL pointer dereference on specially crafted HTTP/2 request",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2024/03/13/2"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Apache HTTP Server",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "status": "affected",
              "version": "2.4.47"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Apache HTTP server would like to thank  LI ZHI XIN from NSFocus for reporting this."
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of these restrictions and HTTP response is sent to the client with a status code indicating why the request was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the offending header was the very first one received or appeared in a a footer. This led to a NULL pointer dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited to DoS the server. This issue affected mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never released."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "other": "important"
            },
            "type": "unknown"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476 NULL Pointer Dereference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2024-05-01T17:10:59.750Z",
        "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
        "shortName": "apache"
      },
      "references": [
        {
          "url": "http://httpd.apache.org/security/vulnerabilities_24.html"
        },
        {
          "name": "[oss-security] 20210609 CVE-2021-31618: Apache httpd: NULL pointer dereference on specially crafted HTTP/2 request",
          "tags": [
            "mailing-list"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2021/06/10/9"
        },
        {
          "url": "https://seclists.org/oss-sec/2021/q2/206"
        },
        {
          "name": "[httpd-cvs] 20210615 svn commit: r1890801 - /httpd/site/trunk/content/security/json/CVE-2021-31618.json",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.apache.org/thread.html/r14b66ef0f4f569fd515a3f96cd4eb58bd9a8ff525cc326bb0359664f%40%3Ccvs.httpd.apache.org%3E"
        },
        {
          "name": "[httpd-cvs] 20210615 svn commit: r1075782 - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_24.html",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.apache.org/thread.html/r783b6558abf3305b17ea462bed4bd66d82866438999bf38cef6d11d1%40%3Ccvs.httpd.apache.org%3E"
        },
        {
          "name": "FEDORA-2021-051639aad4",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2NKJ3ZA3FTSZ2QBBPKS6BYGAWYRABNQQ/"
        },
        {
          "name": "FEDORA-2021-181f29c392",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A73QJ4HPUMU26I6EULG6SCK67TUEXZYR/"
        },
        {
          "name": "[debian-lts-announce] 20210709 [SECURITY] [DLA 2706-1] apache2 security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2021/07/msg00006.html"
        },
        {
          "name": "DSA-4937",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.debian.org/security/2021/dsa-4937"
        },
        {
          "name": "GLSA-202107-38",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://security.gentoo.org/glsa/202107-38"
        },
        {
          "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
        },
        {
          "url": "https://security.netapp.com/advisory/ntap-20210727-0008/"
        },
        {
          "name": "[oss-security] 20240313 Re: CVE-2021-31618: Apache httpd: NULL pointer dereference on specially crafted HTTP/2 request",
          "tags": [
            "mailing-list"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2024/03/13/2"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "NULL pointer dereference on specially crafted HTTP/2 request",
      "workarounds": [
        {
          "lang": "en",
          "value": "On unpatched servers, the `h2` protocol can be disabled by removing it from the `Protocols` configuration. If the `h2` protocol is not enabled, the server is not affected by this vulnerability."
        }
      ],
      "x_generator": {
        "engine": "Vulnogram 0.0.9"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
    "assignerShortName": "apache",
    "cveId": "CVE-2021-31618",
    "datePublished": "2021-06-15T00:00:00.000Z",
    "dateReserved": "2021-04-23T00:00:00.000Z",
    "dateUpdated": "2024-08-03T23:03:33.651Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "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.

Detection rules are retrieved from Rulezet.

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.