Created attachment 35340 [details] Patch fixing this issue mod_authz_dbd segfaults when AuthzDBDQuery is missing in httpd configuration. <Location /moria> AuthName "The Mines of Moria" AuthType Basic AuthBasicProvider dbd AuthDBDUserPWQuery "SELECT password FROM users WHERE username = %s" Require dbd-group istari #AuthzDBDQuery "SELECT groupname FROM groups WHERE username = %s" </Location> Since AuthzDBDQuery is not set, authz_dbd_prepare is not called and therefore dbd_handle remains NULL. This causes segmentation fault, if authz_dbd_login or authz_dbd_group_query functions are triggered, because in the variable initialization is this code: ap_dbd_t *dbd = dbd_handle(r); I moved it after check, if cfg->query is NULL.
Thanks for the report and patch. Fixed in trunk in r1809209. Some small tweaks added (some extra blank lines and no need to initialize dbd to NULL)
Backported in 2.4.x in r1811749 This is part of 2.4.29