Description
ngx_cache_purge 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 ngx_cache_purge module follows symlinks while walking the cache directory tree during purge operations. The module relies on nginx's ngx_walk_tree(), which relies on stat() and therefore follows symlinks.)
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
denji ngx_cache_purge
Default version status: unaffected
2.4.0 to ≤ 2.5.6affected3.0.0 to < 3.0.4affected