ngxcachepurge before 3.0.4 can allow file deletion via a symlink attack in certain situations where nginx and a served application (e.g., WordPress) run under the same user account. The attacker must be able to create a symlink inside the cache path. Version 3.0.4 fixes this for the case of a symlink created at an arbitrary earlier time, but does not resolve an applicable TOCTOU race condition. (The ngxcachepurge module follows symlinks while walking the cache directory tree during purge operations. The module relies on nginx's ngxwalktree(), which relies on stat() and therefore follows symlinks.)