The virDomainListPopulate function in conf/domain_conf.c in libvirt before 1.2.9 does not clean up the lock on the list of domains, which allows remote attackers to cause a denial of service (deadlock) via a NULL value in the second parameter in the virConnectListAllDomains API command. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-3657
