CVE-2021-41098: Improper Restriction of XML External Entity Reference (XXE) in Nokogiri on JRuby
First published: Mon Sep 27 2021(Updated: )
### Severity The Nokogiri maintainers have evaluated this as [**High Severity** 7.5 (CVSS3.0)](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:H/RL:O/RC:C/MAV:N/MAC:L) for JRuby users. (This security advisory does not apply to CRuby users.) ### Impact In Nokogiri v1.12.4 and earlier, **on JRuby only**, the SAX parser resolves external entities by default. Users of Nokogiri on JRuby who parse untrusted documents using any of these classes are affected: - Nokogiri::XML::SAX::Parser - Nokogiri::HTML4::SAX::Parser or its alias Nokogiri::HTML::SAX::Parser - Nokogiri::XML::SAX::PushParser - Nokogiri::HTML4::SAX::PushParser or its alias Nokogiri::HTML::SAX::PushParser ### Mitigation JRuby users should upgrade to Nokogiri v1.12.5 or later. There are no workarounds available for v1.12.4 or earlier. CRuby users are not affected.
Credit: security-advisories@github.com security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Nokogiri Nokogiri | <1.12.5 |
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Reference Links
- https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-2rr5-8q37-2w7h
- https://nvd.nist.gov/vuln/detail/CVE-2021-41098
- https://github.com/sparklemotion/nokogiri/commit/5bf729ff3cc84709ee3c3248c981584088bf9f6d
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/nokogiri/CVE-2021-41098.yml
- https://github.com/advisories/GHSA-2rr5-8q37-2w7h (Advisory)
Frequently Asked Questions
What is the severity of CVE-2021-41098?
The severity of CVE-2021-41098 is high with a CVSS3.0 score of 7.5.
Which software is affected by CVE-2021-41098?
Nokogiri Rubygem versions up to and including 1.12.4 and Nokogiri Nokogiri versions up to but excluding 1.12.5 are affected by CVE-2021-41098.
How can I fix CVE-2021-41098?
To fix CVE-2021-41098, upgrade to Nokogiri version 1.12.5 or later.
Is CRuby affected by CVE-2021-41098?
No, this security advisory does not apply to CRuby users.
Where can I find more information about CVE-2021-41098?
You can find more information about CVE-2021-41098 on the [Nokogiri GitHub Security Advisory](https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-2rr5-8q37-2w7h) and [NVD](https://nvd.nist.gov/vuln/detail/CVE-2021-41098) websites.
- collector/github-advisory-latest
- alias/GHSA-2rr5-8q37-2w7h
- alias/CVE-2021-41098
- collector/github-advisory
- collector/nvd-index
- collector/nvd-cve
- agent/author
- agent/type
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/remedy
- agent/weakness
- agent/title
- agent/last-modified-date
- agent/severity
- agent/references
- agent/description
- agent/tags
- agent/event
- agent/first-publish-date
- package-manager/rubygems
- vendor/nokogiri
- canonical/nokogiri nokogiri