CVE-2013-6400

CVE-2013-6400 describes a denial-of-service or privilege escalation vulnerability in Xen 4.2.x and 4.3.x when using Intel VT-d with assigned PCI devices. The flaw stems from a failure to clear a flag suppressing IOMMU TLB flushes, leading to stale TLB entries. Rated with a CVSS score of 6.8, this vulnerability requires adjacent network access and high attack complexity, but can result in complete compromise of confidentiality, integrity, and availability. There is no known active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion surrounding this CVE.