SB2021101337 - Red Hat Enterprise Linux 8 update for the httpd:2.4 module

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Main Vulnerability Database SB2021101337

SB2021101337 - Red Hat Enterprise Linux 8 update for the httpd:2.4 module

Published: October 13, 2021 Updated: December 18, 2023

Security Bulletin ID SB2021101337
CSH Severity
High
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

High 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) NULL pointer dereference (CVE-ID: CVE-2021-26691)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in mod_session. A a malicious backend server or SessionHeader can trigger a denial of service (DoS) condition.


2) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2021-40438)

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:N/SA:N/E:A/U:Amber


The disclosed vulnerability allows a remote attacker to perform SSRF attacks.

The vulnerability exists due to insufficient validation of user-supplied input within the mod_proxy module in Apache HTTP Server. A remote attacker can send a specially crafted HTTP request with a chosen uri-path and trick the web server to initiate requests to arbitrary systems.

Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.


Remediation

Install update from vendor's website.

References