CVE-2016-10374
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 · uneditedperltidy through 20160302, as used by perlcritic, check-all-the-things, and other software, relies on the current working directory for certain output files and does not have a symlink-attack protection mechanism, which allows local users to overwrite arbitrary files by creating a symlink, as demonstrated by creating a perltidy.ERR symlink that the victim cannot delete.
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 confidenceperltidy through 20160302 writes output files (including .ERR files) to the current working directory without verifying whether a symlink already exists at the target path. A local attacker can pre-create a symlink (e.g., perltidy.ERR pointing to any system file) before the victim runs perltidy, causing arbitrary file overwrite when perltidy follows the symlink and writes to it.
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<= 2016-03-02CVSS 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
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
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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Check installed perltidy versionRun 'perltidy --version' or 'perltidy -v' to identify the version numberAffected if The version displayed is 2016-03-02 or earlier (any version <= 2016-03-02)
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Verify symlink creation behaviorCreate a test directory, place a file named 'perltidy.ERR' as a symlink to a test file, run perltidy on any .pl file in that directory, then check if the symlink target was overwrittenAffected if perltidy follows the symlink and overwrites the target file instead of refusing to write or creating a new file
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Check working directory permissionsInspect the directory where perltidy will be run using 'ls -la' - look for world-writable or group-writable directories where untrusted users may have write accessAffected if The working directory is writable by other users, allowing them to pre-create symlinks before perltidy runs
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Identify if .ERR file generation is triggeredRun perltidy with options that produce .ERR files (e.g., syntactically invalid Perl code) and check if .ERR files are created in the current working directoryAffected if perltidy writes .ERR output files to the current working directory rather than a controlled location
You are affected if you run perltidy version 2016-03-02 or earlier in a directory accessible to untrusted local users, and perltidy creates output files (including .ERR files) in that directory without detecting pre-existing symlinks.
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 dataDo not run perltidy in directories accessible to untrusted local users, or ensure the working directory is secured. The upstream fix requires perltidy to detect and refuse to follow symlinks when creating output files.
- Consultation3.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-10374 — 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-2016-10374 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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