The affected asset is vulnerable to this vulnerability ONLY if an attacker is able to get Apache to parse an untrusted XML document. Review your web server configuration for validation. A buffer over-read flaw was found in the bundled expat library. An attacker who is able to get Apache to parse an untrused XML document (for example through mod_dav) may be able to cause a crash. This crash would only be a denial of service if using the worker MPM.