Freebsd » Freebsd » 6.4 : Security Vulnerabilities, CVEs, Published In 2009 (Memory corruption)

Race condition in the Pipe (IPC) close function in FreeBSD 6.3 and 6.4 allows local users to cause a denial of service (crash) or gain privileges via vectors related to kqueues, which triggers a use after free, leading to a NULL pointer dereference or memory corruption.