An unauthenticated OS command injection vulnerability exists within Xdebug versions 2.5.5 and earlier, a PHP debugging extension developed by Derick Rethans. When remote debugging is enabled, Xdebug listens on port 9000 and accepts debugger protocol commands without authentication. An attacker can send a crafted eval command over this interface to execute arbitrary PHP code, which may invoke system-level functions such as system() or passthru(). This results in full compromise of the host under the privileges of the web server user.
https://www.vulncheck.com/advisories/xdebug-remote-debugger-unauth-os-command-execution
https://www.fortiguard.com/encyclopedia/ips/46000
https://www.exploit-db.com/exploits/44568
https://kirtixs.com/blog/2015/11/13/xpwn-exploiting-xdebug-enabled-servers/
http://web.archive.org/web/20231226215418/https://paper.seebug.org/397/
Published: 2025-07-23
Updated: 2025-07-25
Base Score: 10
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
Severity: Critical
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 9.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: Critical
EPSS: 0.00759