CWE-476 NULL Pointer Dereference vulnerability in the evalExpr() function of GoAhead Web Server (version <= 6.0.0) when compiled with the ME_GOAHEAD_JAVASCRIPT flag. This vulnerability allows a remote attacker with the privileges to modify JavaScript template (JST) files to trigger a crash and cause a Denial of Service (DoS) by providing malicious templates.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.