An issue was discovered in PHP 7.3.x before 7.3.0alpha3, 7.2.x before 7.2.8, and before 7.1.20. The php-fpm master process restarts a child process in an endless loop when using program execution functions (e.g., passthru, exec, shell_exec, or system) with a non-blocking STDIN stream, causing this master process to consume 100% of the CPU, and consume disk space with a large volume of error logs, as demonstrated by an attack by a customer of a shared-hosting facility.
The product does not properly control the allocation and maintenance of a limited resource.
| Link | Tags |
|---|---|
| https://github.com/php/php-src/blob/PHP-7.1.20/NEWS#L20-L22 | third party advisory |
| https://bugs.php.net/bug.php?id=70185 | issue tracking exploit vendor advisory |
| https://bugs.php.net/bug.php?id=75968 | issue tracking exploit vendor advisory |
| https://usn.ubuntu.com/3766-1/ | third party advisory vendor advisory |
| https://bugs.php.net/bug.php?id=73342https://github.com/php/php-src/pull/3287 | issue tracking exploit vendor advisory |
| https://github.com/php/php-src/commit/69dee5c732fe982c82edb17d0dbc3e79a47748d8 | third party advisory patch |
| https://www.futureweb.at/security/CVE-2015-9253/ | third party advisory exploit |
| https://usn.ubuntu.com/4279-1/ | vendor advisory |