Apache httpd 1.3.37, 2.0.59, and 2.2.4 with the Prefork MPM module, allows local users to cause a denial of service by modifying the worker_score and process_score arrays to reference an arbitrary process ID, which is sent a SIGUSR1 signal from the master process, aka "SIGUSR1 killer."
| Software | From | Fixed in |
|---|---|---|
| apache / http_server | 2.2.0 | 2.2.6 |
| apache / http_server | 2.0.0 | 2.0.61 |
| apache / http_server | 1.3.0 | 1.3.39 |
| fedoraproject / fedora | 7 | 7.x |
| redhat / enterprise_linux_server | 5.0 | 5.0.x |
| redhat / enterprise_linux_workstation | 5.0 | 5.0.x |
| redhat / enterprise_linux_desktop | 5.0 | 5.0.x |
| canonical / ubuntu_linux | 7.04 | 7.04.x |
| canonical / ubuntu_linux | 6.10 | 6.10.x |
| canonical / ubuntu_linux | 6.06 | 6.06.x |