CVE-2013-2094

What it actually does

Incorrect integer data type in perf_swevent_init allows crafted perf_event_open calls to trigger out-of-bounds memory access, enabling local privilege escalation to root.

Why it matters to the business

Attackers who already have a shell on affected Linux systems can obtain full administrative control, leading to data theft, ransomware deployment, or persistent backdoors; the long-standing KEV status and 2022 CISA deadline underscore the need for immediate patching on any remaining legacy deployments.

How an attack unfolds

An attacker with local access invokes perf_event_open with specially chosen parameters that exploit the integer-type mismatch in perf_swevent_init, corrupting kernel memory structures to disable protections and execute arbitrary code with root privileges; public exploits have been used in the wild by multiple actors.

How to fix it

Upgrade the Linux kernel to version 3.8.9 or later; rebuild and reboot all affected hosts; where immediate patching is impossible, restrict unprivileged use of perf_event_open via sysctl or seccomp filters.

How to confirm the fix worked

Confirm kernel version is at least 3.8.9; run automated vulnerability scanners against the running kernel; verify that perf_event_paranoid is set to a restrictive value and that no unprivileged perf access remains.

Typical attack path

1. Obtain local shell access via unprivileged account or weak service
2. Compile or drop a crafted exploit binary that calls perf_event_open with malicious event configuration
3. Trigger the integer-type flaw to achieve kernel memory corruption
4. Escalate to root, disable SELinux/AppArmor, and install persistence or exfiltrate data

How to detect it

Search kernel audit logs and syscall traces for anomalous perf_event_open calls; inspect for unexpected root processes spawned shortly after perf-related activity; review historical exploit artifacts such as dropped binaries containing perf_event_open patterns.

What your security team should do

• Immediately inventory all systems still running kernels older than 3.8.9 and schedule emergency kernel upgrades
• Block or heavily restrict perf_event_open for non-root users via system-wide configuration
• Enable kernel exploit detection and memory-integrity monitoring on remaining legacy hosts
• Review logs for historical perf_event_open activity on any unpatched systems