Arch Linux Security Advisory ASA-201910-14 ========================================== Severity: Critical Date : 2019-10-25 CVE-ID : CVE-2019-11043 Package : php Type : arbitrary code execution Remote : Yes Link : https://security.archlinux.org/AVG-1052 Summary ======= The package php before version 7.3.11-1 is vulnerable to arbitrary code execution. Resolution ========== Upgrade to 7.3.11-1. # pacman -Syu "php>=7.3.11-1" The problem has been fixed upstream in version 7.3.11. Workaround ========== If nginx and php-fpm share the same filesystem, one can first check the script actually exists, so the malicious request will never make it to php-fpm (it is usually done using something like `try_files $uri =404`). Or there may be cgi.fix_pathinfo=0 which will also prevent exploitation. Description =========== A buffer underflow issue has been found in the php-fpm component of php before 7.3.11, 7.2.24 and 7.1.33, leading to remote code execution in certain nginx + php-fpm configurations. This vulnerability can be exploited if the fastcgi_split_path_info directive contains a regexp that can be broken by an attacker by supplying %0a in the path info which results in the fastcgi_param PATH_INFO being empty. Impact ====== A remote attacker is able to execute arbitrary code on the affected host by supplying %0a in the path info if php-fpm is used with a vulnerable nginx configuration. References ========== https://bugs.php.net/bug.php?id=78599 https://git.php.net/?p=php-src.git;a=commitdiff;h=19e17d3807e6cc0b1ba9443ec5... https://github.com/neex/phuip-fpizdam https://security.archlinux.org/CVE-2019-11043