Apache Httpd < 2.4.27 : Uninitialized memory reflection in mod_auth_digest

The value placeholder in [Proxy-]Authorization headers of type ‘Digest’ was not initialized or reset before or between successive key=value assignments. by mod_auth_digest. Providing an initial key with no ‘=’ assignment could reflect the stale value of uninitialized pool memory used by the prior request, leading to leakage of potentially confidential information, and a segfault.