Arch Linux Security Advisory ASA-202110-1 ========================================= Severity: Critical Date : 2021-10-21 CVE-ID : CVE-2021-42013 Package : apache Type : directory traversal Remote : Yes Link : https://security.archlinux.org/AVG-2450 Summary ======= The package apache before version 2.4.51-1 is vulnerable to directory traversal. Resolution ========== Upgrade to 2.4.51-1. # pacman -Syu "apache>=2.4.51-1" The problem has been fixed upstream in version 2.4.51. Workaround ========== None. Description =========== It was found that the fix for CVE-2021-41773 in Apache HTTP Server 2.4.50 was insufficient. 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 only affects Apache 2.4.49 and Apache 2.4.50 and not earlier versions. Impact ====== A remote attacker could trick the HTTP server into executing arbitrary executables in its file system through path traversal. References ========== https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2021-42013 https://twitter.com/roman_soft/status/1446252280597078024 https://github.com/icing/blog/blob/main/httpd-2.4.50.md https://svn.apache.org/viewvc?view=revision&revision=1893971 https://security.archlinux.org/CVE-2021-42013