CVE-2012-3495

CVE-2012-3495 describes a denial-of-service vulnerability in Xen 4.1.x and Citrix XenServer 6.0.2 and earlier. The physdev_get_free_pirq hypercall mishandles the return value of get_free_pirq, using it as an array index without proper validation. This allows a guest OS user to trigger an invalid memory write, leading to a host crash and potential privilege escalation. With a CVSS score of 6.1, this vulnerability is of medium severity. It requires local access (AV:L) with low attack complexity (AC:L) and no authentication (Au:N), potentially leading to partial confidentiality (C:P), partial integrity (I:P), and complete availability (A:C) impact. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE. It is not listed in CISA's KEV catalog.