CVE-2021-44224
httpd: possible NULL dereference or SSRF in forward proxy configurations
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · December 20, 2021
Updated · November 2, 2026
Description
There's a null pointer dereference and server-side request forgery flaw in httpd's mod_proxy module, when it is configured to be used as a forward proxy. A crafted packet could be sent on the adjacent network to the forward proxy that could cause a crash, or potentially SSRF via misdirected Unix Domain Socket requests. In the worst case, this could cause a denial of service or compromise to confidentiality of data.
Statement
This flaw does not affect httpd configurations that do not use forward proxy functionality (configurations where ProxyRequests is turned off).
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.1CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H
CWE-918 · Server-Side Request Forgery