FreeBSDOperating system
CVE-2013-2171
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe vm_map_lookup function in sys/vm/vm_map.c in the mmap implementation in the kernel in FreeBSD 9.0 through 9.1-RELEASE-p4 does not properly determine whether a task should have write access to a memory location, which allows local users to bypass filesystem write permissions and consequently gain privileges via a crafted application that leverages read permissions, and makes mmap and ptrace system calls.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe vm_map_lookup function in FreeBSD's kernel mmap implementation (sys/vm/vm_map.c) fails to properly validate write access permissions, allowing local users to bypass filesystem write permissions and escalate privileges through crafted applications leveraging read permissions via mmap and ptrace system calls.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FreeBSDOperating system
= 9.0= 9.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- M
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/AC:M/Au:N/C:C/I:C/A:C
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the FreeBSD versionRun `uname -a` or `freebsd-version -k` to determine the installed FreeBSD version and kernel versionAffected if The version shows 9.0 or 9.1 (any patch level)
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Check the patch level on FreeBSD 9.1If running 9.1, run `uname -a` to see the full release string (for example, 9.1-RELEASE-p3) or check `freebsd-version` outputAffected if Running 9.1-RELEASE-p3 or earlier (patch level less than p4)
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Confirm 9.0 is unpatchedVerify the exact 9.0 release version via `uname -r` outputAffected if Any 9.0 release (9.0-RELEASE, 9.0-RELEASE-p1, etc.) is affected since the fix was in 9.1-RELEASE-p4
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Check for active kernel exploitation indicatorsReview system logs and running processes for unusual use of mmap with MAP_PRIVATE and PROT_READ combined with ptrace activity, though this is difficult to detect definitivelyAffected if Unusual processes combining mmap read-only mappings with ptrace operations on other processes
A system is affected if it runs FreeBSD 9.0 (any patch level) or FreeBSD 9.1 with patch level earlier than p4, as these versions contain the vulnerable vm_map_lookup code that fails to enforce write permission checks on memory mappings.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply the appropriate FreeBSD security patch for CVE-2013-2171 (update to a version beyond 9.1-RELEASE-p4) and reboot into the patched kernel. Verify that memory mapping behaviors now correctly enforce write permission checks.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-2171 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2013-2171 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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