The proxy functionality in (1) mod_proxy_ajp.c in the mod_proxy_ajp module and (2) mod_proxy_http.c in the mod_proxy_http module in the Apache HTTP Server 2.4.x before 2.4.3 does not properly determine the situations that require closing a back-end connection, which allows remote attackers to obtain sensitive information in opportunistic circumstances by reading a response that was intended for a different client.