SB2021100528 - Fedora 35 update for httpd

CSH
CYBERSECURITY HELP
Sign In REGISTER

Main Vulnerability Database SB2021100528

SB2021100528 - Fedora 35 update for httpd

Published: October 5, 2021

Security Bulletin ID SB2021100528
Severity
Critical
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

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

Description

This security bulletin contains information about 4 secuirty vulnerabilities.


1) NULL pointer dereference (CVE-ID: CVE-2021-41524)

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

The vulnerability exists due to a NULL pointer dereference error when processing HTTP/2 requests. A remote attacker can send a specially crafted HTTP/2 request to the affected Apache HTTP server and perform a denial of service (DoS) attack.


2) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2021-33193)

The vulnerability allows a remote attacker to preform HTTP/2 request smuggling attacks.

The vulnerability exists due to improper validation of HTTP/2 requests in mod_proxy in Apache HTTP Server. A remote attacker can send a specially crafted HTTP/2 request to the server and smuggle arbitrary HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison web server cache and perform phishing attacks.


3) OS Command Injection (CVE-ID: CVE-2021-42013)

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to insufficient fix for the path traversal vulnerability #VU57063 (CVE-2021-41733). A remote unauthenticated attacker can send a specially crafted HTTP request to the affected server and execute arbitrary OS commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


4) Path traversal (CVE-ID: CVE-2021-41773)

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences. A remote attacker can send a specially crafted HTTP request to map URLs to files outside the expected document root. If files outside of the document root are not protected by "require all denied" these requests can succeed. Additionally this flaw could leak the source of interpreted files like CGI scripts.

The vulnerability can be used to execute arbitrary OS commands on the system.

Note, the vulnerability is being actively exploited in the wild.


Remediation

Install update from vendor's website.

References