The Solaris pollset feature in the Event Port backend in poll/unix/port.c in the Apache Portable Runtime (APR) library before 1.3.9, as used in the Apache HTTP Server before 2.2.14 and other products, does not properly handle errors, which allows remote attackers to cause a denial of service (daemon hang) via unspecified HTTP requests, related to the prefork and event MPMs.

Apache APR is vulnerable to a denial of service, caused by insufficient randomization of hash data structures. By sending multiple specially-crafted HTTP POST requests to an affected application containing conflicting hash key values, a remote attacker could exploit this vulnerability to cause the consumption of CPU resources.