GHSA-fq42-c5rg-92c2
Vulnerable dependencies in Nokogiri
Blast Radius
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Description
Summary
Nokogiri v1.13.2 upgrades two of its packaged dependencies:
Those library versions address the following upstream CVEs:
- libxslt: CVE-2021-30560 (CVSS 8.8, High severity)
- libxml2: CVE-2022-23308 (Unspecified severity, see more information below)
Those library versions also address numerous other issues including performance improvements, regression fixes, and bug fixes, as well as memory leaks and other use-after-free issues that were not assigned CVEs.
Please note that this advisory only applies to the CRuby implementation of Nokogiri < 1.13.2, and only if the packaged libraries are being used. If you've overridden defaults at installation time to use system libraries instead of packaged libraries, you should instead pay attention to your distro's libxml2 and libxslt release announcements.
Mitigation
Upgrade to Nokogiri >= 1.13.2.
Users who are unable to upgrade Nokogiri may also choose a more complicated mitigation: compile and link an older version Nokogiri against external libraries libxml2 >= 2.9.13 and libxslt >= 1.1.35, which will also address these same CVEs.
Impact
libxslt CVE-2021-30560
- CVSS3 score: 8.8 (High)
- Fixed by https://gitlab.gnome.org/GNOME/libxslt/-/commit/50f9c9c
All versions of libxslt prior to v1.1.35 are affected.
Applications using untrusted XSL stylesheets to transform XML are vulnerable to a denial-of-service attack and should be upgraded immediately.
libxml2 CVE-2022-23308
- As of the time this security advisory was published, there is no officially published information available about this CVE's severity. The above NIST link does not yet have a published record, and the libxml2 maintainer has declined to provide a severity score.
- Fixed by https://gitlab.gnome.org/GNOME/libxml2/-/commit/652dd12
- Further explanation is at https://mail.gnome.org/archives/xml/2022-February/msg00015.html
The upstream commit and the explanation linked above indicate that an application may be vulnerable to a denial of service, memory disclosure, or code execution if it parses an untrusted document with parse options DTDVALID set to true, and NOENT set to false.
An analysis of these parse options:
- While
NOENTis off by default for Document, DocumentFragment, Reader, and Schema parsing, it is on by default for XSLT (stylesheet) parsing in Nokogiri v1.12.0 and later. DTDVALIDis an option that Nokogiri does not set for any operations, and so this CVE applies only to applications setting this option explicitly.
It seems reasonable to assume that any application explicitly setting the parse option DTDVALID when parsing untrusted documents is vulnerable and should be upgraded immediately.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | nokogiri | all versions | 1.13.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nokogiri. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update nokogiri to 1.13.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fq42-c5rg-92c2 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether GHSA-fq42-c5rg-92c2 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-fq42-c5rg-92c2. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-fq42-c5rg-92c2 in your dependencies?
O3 detects GHSA-fq42-c5rg-92c2 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.