CVE-2013-2596

CVE-2013-2596 is an integer overflow in the fb_mmap function in drivers/video/fbmem.c of the Linux kernel, a memory-mapping routine for framebuffer devices. The flaw is triggered when the kernel performs the arithmetic used to map framebuffer memory, and the overflowed calculation can yield an incorrect mapping that an attacker can leverage. An attacker who successfully exploits it gains elevated privileges on the affected system. Any system running an affected Linux kernel build is exposed, with the practical attack surface concentrated on systems where users can memory-map framebuffer devices; the specific vulnerable version range is not specified in the available data. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2022-09-15, indicating exploitation in the wild, though no public proof-of-concept is known, ransomware use is unknown, and EPSS puts 30-day exploitation probability at 3.2% (87th percentile).

What to do: Apply updated kernel packages per your distribution or vendor's instructions, as CISA's required action directs, prioritizing internet-exposed and multi-user systems. As an interim mitigation, audit which systems permit unprivileged access to framebuffer devices (/dev/fb*) and restrict that access. Because fixed version numbers are not specified in the available data, confirm exact patched kernel versions with your vendor before declaring remediation complete.