CVE-2016-5195 is a high-severity (CVSS 7) CWE-362 vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-03) — treat it as actively exploited and patch now. A fix is available — see the affected versions and patch details below.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-03-03. Federal agencies were required to remediate by 2022-03-24.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2016-5195.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2016-5195 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 396,257 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect handling of a copy-on-write (COW) feature to write to a read-only memory mapping, as exploited in the wild in October 2016, aka "Dirty COW."
Affected Products
ubuntu linuxcanonicaldebian linuxdebianfedorafedoraprojectlinux kernellinuxcloud backupnetapphci storage nodesnetappResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Linux Kernel 2.6.22 < 3.9 - 'Dirty COW /proc/self/mem' Race Condition Privilege Escalation (/etc/passwd Method)
by Gabriele Bonacini · Nov 27, 2016
Linux Kernel 2.6.22 < 3.9 - 'Dirty COW' 'PTRACE_POKEDATA' Race Condition Privilege Escalation (/etc/passwd Method)
by FireFart · Nov 28, 2016
Linux Kernel 2.6.22 < 3.9 - 'Dirty COW PTRACE_POKEDATA' Race Condition (Write Access Method)
by Phil Oester · Oct 26, 2016
Linux Kernel 2.6.22 < 3.9 - 'Dirty COW' /proc/self/mem Race Condition (Write Access Method)
by Phil Oester · Oct 19, 2016
Linux Kernel 2.6.22 < 3.9 (x86/x64) - 'Dirty COW /proc/self/mem' Race Condition Privilege Escalation (SUID Method)
by Robin Verton · Oct 21, 2016
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2016-5195, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7 and MRG 2.x. This issue has been rated as having Important security impact.
Please see bug 1384344 comment #13 (https://bugzilla.redhat.com/show_bug.cgi?id=1384344#c13) for details on how to mitigate this issue.Source: Red Hat security advisory for CVE-2016-5195 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 5 | kernel-0:2.6.18-416.el5 | RHSA-2016:2124 |
| Red Hat Enterprise Linux 5.6 Long Life | kernel-0:2.6.18-238.57.1.el5 | RHSA-2016:2127 |
| Red Hat Enterprise Linux 5.9 Long Life | kernel-0:2.6.18-348.32.1.el5 | RHSA-2016:2126 |
| Red Hat Enterprise Linux 6 | kernel-0:2.6.32-642.6.2.el6 | RHSA-2016:2105 |
| Red Hat Enterprise Linux 6.2 Advanced Update Support | kernel-0:2.6.32-220.68.1.el6 | RHSA-2016:2132 |
| Red Hat Enterprise Linux 6.4 Advanced Update Support | kernel-0:2.6.32-358.75.1.el6 | RHSA-2016:2133 |
| Red Hat Enterprise Linux 6.5 Advanced Update Support | kernel-0:2.6.32-431.75.1.el6 | RHSA-2016:2120 |
| Red Hat Enterprise Linux 6.6 Extended Update Support | kernel-0:2.6.32-504.54.1.el6 | RHSA-2016:2128 |
Frequently Asked Questions
Is CVE-2016-5195 in your dependencies?
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