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CVE-2021-31618 Detail

Description

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.


Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  7.5 HIGH
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
http://httpd.apache.org/security/vulnerabilities_24.html Release Notes  Vendor Advisory 
http://www.openwall.com/lists/oss-security/2021/06/10/9 Mailing List  Third Party Advisory 
https://lists.apache.org/thread.html/r14b66ef0f4f569fd515a3f96cd4eb58bd9a8ff525cc326bb0359664f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r783b6558abf3305b17ea462bed4bd66d82866438999bf38cef6d11d1%40%3Ccvs.httpd.apache.org%3E
https://lists.debian.org/debian-lts-announce/2021/07/msg00006.html Mailing List  Third Party Advisory 
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2NKJ3ZA3FTSZ2QBBPKS6BYGAWYRABNQQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A73QJ4HPUMU26I6EULG6SCK67TUEXZYR/
https://seclists.org/oss-sec/2021/q2/206 Mailing List  Third Party Advisory 
https://security.gentoo.org/glsa/202107-38 Third Party Advisory 
https://security.netapp.com/advisory/ntap-20210727-0008/ Third Party Advisory 
https://www.debian.org/security/2021/dsa-4937 Third Party Advisory 
https://www.oracle.com/security-alerts/cpuoct2021.html Patch  Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-476 NULL Pointer Dereference cwe source acceptance level NIST   Provider acceptance level Apache Software Foundation  

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Change History

12 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-31618
NVD Published Date:
06/15/2021
NVD Last Modified:
11/06/2023
Source:
Apache Software Foundation