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Advisory details: apache_httpd / CVE-2021-31618
Advisory ID apache_httpd/CVE-2021-31618
Aliases
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-476 NULL Pointer Dereference
System Score Found at
apache_httpd important
Reference id Reference type URL
CVE-2021-31618 https://httpd.apache.org/security/json/CVE-2021-31618.json
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
There are no known vectors.

Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2024-05-20T16:18:33Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2021/31xxx/CVE-2021-31618.json

Source Advisory: vulnrichment/CVE-2021-31618

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'yes'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]