CVE-2022-23476: Nokogiri Unchecked Return Value From XmlTextReaderExpand Vulnerability

HIGH
Advisory Identifier: GHSA-qv4q-mr5r-qprj
Share
CVSS 7.5
CWE-252 CWE-476
Published
Advisory Summary

CVE-2022-23476 is a HIGH (CVSS 7.5) unchecked return value from xmltextreaderexpand vulnerability (CWE-252: Unchecked Return Value) affecting Nokogiri libraries in the RubyGems ecosystem. The issue involves unchecked return value from xmltextreaderexpand. Remediation is available by upgrading affected packages to version 1.13.10.

CVE-2022-23476 at a Glance

CVE Identifier CVE-2022-23476
GHSA Identifier GHSA-qv4q-mr5r-qprj
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-252: Unchecked Return Value
Affected Product Nokogiri
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2022-23476

To remediate this vulnerability, upgrade all affected Nokogiri dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

nokogiri fixed: 1.13.10 
Upgrade nokogiri to 1.13.10
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for nokogiri

How to Check if You Are Affected

To determine whether your application is affected by CVE-2022-23476, inspect your project dependencies for Nokogiri:

inspect dependencies for nokogiri

Analyze the terminal output to locate any version of Nokogiri in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.13.10), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-252: Unchecked Return Value, where the product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions. In Nokogiri, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Summary Nokogiri `1.13.8, 1.13.9` fails to check the return value from `xmlTextReaderExpand` in the method `Nokogiri::XML::Reader#attribute_hash`. This can lead to a null pointer exception when invalid markup is being parsed. For applications using `XML::Reader` to parse untrusted inputs, this may potentially be a vector for a denial of service attack. ## Mitigation Upgrade to Nokogiri `>= 1.13.10`. Users may be able to search their code for calls to either `XML::Reader#attributes` or `XML::Reader#attribute_hash` to determine if they are affected. ## Severity The Nokogiri maintainers have evaluated this as [High Severity 7.5 (CVSS3.1)](https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). ## References - [CWE - CWE-252: Unchecked Return Value (4.9)](https://cwe.mitre.org/data/definitions/252.html) - [CWE - CWE-476: NULL Pointer Dereference (4.9)](https://cwe.mitre.org/data/definitions/476.html) ## Credit This vulnerability was responsibly reported by @davidwilemski.

CVE-2022-23476 Affected Nokogiri Versions

1 component(s)
Fixed Versions:
1.13.10
Product / Package Ecosystem Affected Versions Fixed Version
nokogiri
gem/nokogiri
RubyGems
≥ 1.13.8
< 1.13.10
1.13.10

References

GitHub Advisory / Wiki ADVISORY
https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-qv4q-mr5r-qprj
NVD — CVE-2022-23476 NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-23476
Security Fix Commit FIX COMMIT
https://github.com/sparklemotion/nokogiri/commit/85410e38410f670cbbc8c5b00d07b843caee88ce
Security Fix Commit FIX COMMIT
https://github.com/sparklemotion/nokogiri/commit/9fe0761c47c0d4270d1a5220cfd25de080350d50
Nokogiri Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/nokogiri/CVE-2022-23476.yml
Nokogiri Source Repository REPOSITORY
https://github.com/sparklemotion/nokogiri

Frequently Asked Questions

What is CVE-2022-23476?
CVE-2022-23476 is a security vulnerability in Nokogiri involving Unchecked return value from xmlTextReaderExpand under CWE-252: Unchecked Return Value.
Which Nokogiri versions are affected?
Affected versions include releases prior to 1.13.10 across affected packages: nokogiri.
What version fixes CVE-2022-23476?
Upgrading to 1.13.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nokogiri affected?
Yes, nokogiri is affected in releases prior to 1.13.10. Upgrade your dependency to 1.13.10 or later.
What is the CVSS score of CVE-2022-23476?
CVE-2022-23476 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2022-23476?
CVE-2022-23476 is classified under CWE-252: Unchecked Return Value (The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.).
How can I check RubyGems dependencies for CVE-2022-23476?
Run the dependency tree command: 'inspect dependencies for nokogiri'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-qv4q-mr5r-qprj",
  "modified" : "2022-12-08T03:03:33Z",
  "published" : "2022-12-08T03:03:33Z",
  "aliases" : [ "CVE-2022-23476" ],
  "summary" : "Unchecked return value from xmlTextReaderExpand",
  "details" : "## Summary\n\nNokogiri `1.13.8, 1.13.9` fails to check the return value from `xmlTextReaderExpand` in the method `Nokogiri::XML::Reader#attribute_hash`. This can lead to a null pointer exception when invalid markup is being parsed. \n\nFor applications using `XML::Reader` to parse untrusted inputs, this may potentially be a vector for a denial of service attack.\n\n\n## Mitigation\n\nUpgrade to Nokogiri `>= 1.13.10`.\n\nUsers may be able to search their code for calls to either `XML::Reader#attributes` or `XML::Reader#attribute_hash` to determine if they are affected.\n\n\n## Severity\n\nThe Nokogiri maintainers have evaluated this as [High Severity 7.5 (CVSS3.1)](https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).\n\n\n## References\n\n- [CWE - CWE-252: Unchecked Return Value (4.9)](https://cwe.mitre.org/data/definitions/252.html)\n- [CWE - CWE-476: NULL Pointer Dereference (4.9)](https://cwe.mitre.org/data/definitions/476.html)\n\n\n## Credit\n\nThis vulnerability was responsibly reported by @davidwilemski.\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "nokogiri"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.13.8"
      }, {
        "fixed" : "1.13.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-qv4q-mr5r-qprj"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2022-23476"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/sparklemotion/nokogiri/commit/85410e38410f670cbbc8c5b00d07b843caee88ce"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/sparklemotion/nokogiri/commit/9fe0761c47c0d4270d1a5220cfd25de080350d50"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/nokogiri/CVE-2022-23476.yml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/sparklemotion/nokogiri"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-252", "CWE-476" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-12-08T03:03:33Z",
    "nvd_published_at" : "2022-12-08T04:15:00Z"
  }
}