CVE-2013-4329

CVE-2013-4329 describes a privilege escalation and denial-of-service vulnerability in the xenlight library (libxl) of Xen versions 4.0.x through 4.2.x. When the IOMMU is disabled, the library prematurely grants access to busmastering-capable PCI passthrough devices to local HVM guest domains. This allows a malicious guest to execute DMA instructions before IOMMU setup is complete, leading to privilege escalation or a denial of service. The vulnerability has a CVSS score of 6.5, indicating a medium severity, with an adjacent attack vector and high attack complexity requiring authenticated access. There is no evidence of active exploitation, publicly available exploit code, or significant community discussion or media coverage for this CVE.