1. Home
  2. Mapping Frameworks
  3. Known Exploited Vulnerabilities Home
  4. Apache HTTP Server Path Traversal Vulnerability

Known Exploited Vulnerabilities CVE-2021-41773 Mappings

A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied", these requests can succeed. If CGI scripts are also enabled for these aliased pathes, this could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 was found to be incomplete, see CVE-2021-42013.

Mappings

Capability ID Capability Description Mapping Type ATT&CK ID ATT&CK Name Notes
CVE-2021-41773 Apache HTTP Server Path Traversal Vulnerability primary_impact T1059 Command and Scripting Interpreter
Comments
CVE-2021-41773 is a path traversal vulnerability in Apache HTTP Server 2.4.49 that allows an attacker to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied," these requests can succeed. If CGI scripts are also enabled for these aliased paths, this could allow for remote code execution.
References
  1. https://github.com/battleoverflow/apache-traversal
  2. https://blog.qualys.com/vulnerabilities-threat-research/2021/10/27/apache-http-server-path-traversal-remote-code-execution-cve-2021-41773-cve-2021-42013
CVE-2021-41773 Apache HTTP Server Path Traversal Vulnerability exploitation_technique T1210 Exploitation of Remote Services
Comments
CVE-2021-41773 is a path traversal vulnerability in Apache HTTP Server 2.4.49 that allows an attacker to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied," these requests can succeed. If CGI scripts are also enabled for these aliased paths, this could allow for remote code execution.
References
  1. https://blog.qualys.com/vulnerabilities-threat-research/2021/10/27/apache-http-server-path-traversal-remote-code-execution-cve-2021-41773-cve-2021-42013
  2. https://github.com/battleoverflow/apache-traversal