The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. In 3.0.12, a peer offering only Digest qop=auth-int causes mutual-authentication verification to be skipped. AuthenticatorUtils.computeExpectedRspAuth returns no expected value for auth-int, and Interceptors treats that result as unverifiable but nonfatal, so a response with an invalid rspauth value is accepted. A peer that does not know the shared secret can therefore be accepted as the authenticated server. This issue is fixed in version 3.0.13.