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TI-2009-04253 Aliases CVE-2009-4492GHSA-6mq2-37j5-w6r6

WEBrick 1.3.1 in Ruby 1.8.6 through patchlevel 383, 1.8.7 through patchlevel 248…

Priority MEDIUM 49CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
— Not recorded in CVSS 2.0
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Partial · Partial · Partial
Fix status
Fixed

Attack profile from CVSS 2.0 · NVD. Fix status from CNA, GitHub and Red Hat.

Summary

WEBrick 1.3.1 in Ruby 1.8.6 through patchlevel 383, 1.8.7 through patchlevel 248, 1.8.8dev, 1.9.1 through patchlevel 376, and 1.9.2dev writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to modify a window's title, or possibly execute arbitrary commands or overwrite files, via an HTTP request containing an escape sequence for a terminal emulator.

Why it matters now

EPSS 0.1623 96th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed webrick (RubyGems): 1.4.0Red Hat: 2 advisories

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
—webrick (RubyGems)before 1.4.01.4.0Patch availableGHSA-6mq2-37j5-w6r6
  • — Vendor— Affected all versions Fixed in — No fix listed CNA
  • webrick (RubyGems) Vendor— Affected before 1.4.0 Fixed in 1.4.0 Patch available GHSA-6mq2-37j5-w6r6

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:ruby-lang:webrick:1.3.1:*:*:*:*:ruby:*:*1.3.1Vulnerableruby
cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*1.8.6 – 1.8.6.383; 1.8.7 – 1.8.7.248; 1.9.1 – 1.9.1.376Running onruby
  • cpe:2.3:a:ruby-lang:webrick:1.3.1:*:*:*:*:ruby:*:* Versions 1.3.1 Vulnerable ·ruby
  • cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:* Versions 1.8.6 – 1.8.6.383; 1.8.7 – 1.8.7.248; 1.9.1 – 1.9.1.376 Running on ·ruby

Remediation

  • Fix · GHSA-6mq2-37j5-w6r6 webrick (RubyGems) Fixed in 1.4.0 Advisory →

Red Hat 2 advisories

  • RHSA-2011:0909 Released 2011-06-28 · Red Hat rating Moderate
    ruby security update
    • Red Hat Enterprise Linux (v. 5.6.z server) ruby-1.8.5-19.el5_6.1, ruby-1.8.5-19.el5_6.1.i386, ruby-1.8.5-19.el5_6.1.ia64 +33
  • RHSA-2011:0908 Released 2011-06-28 · Red Hat rating Moderate
    ruby security update
    • Red Hat Enterprise Linux AS version 4 irb-1.8.1-16.el4, irb-1.8.1-16.el4.i386, irb-1.8.1-16.el4.ia64 +25
    • Red Hat Enterprise Linux Desktop version 4 irb-1.8.1-16.el4, irb-1.8.1-16.el4.i386, ruby-1.8.1-16.el4 +11
    • Red Hat Enterprise Linux ES version 4 irb-1.8.1-16.el4, irb-1.8.1-16.el4.i386, irb-1.8.1-16.el4.ia64 +18
    • Red Hat Enterprise Linux WS version 4 irb-1.8.1-16.el4, irb-1.8.1-16.el4.i386, irb-1.8.1-16.el4.ia64 +18

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux (v. 5.6.z server)Fixed RHSA-2011:0909
Red Hat Enterprise Linux AS version 4Fixed RHSA-2011:0908
Red Hat Enterprise Linux Desktop version 4Fixed RHSA-2011:0908
Red Hat Enterprise Linux ES version 4Fixed RHSA-2011:0908
Red Hat Enterprise Linux WS version 4Fixed RHSA-2011:0908

Timeline

  1. 2026-10-02 Threatist record created from CVE-2009-4492
  2. 2026-10-03 Alias added: GHSA-6mq2-37j5-w6r6

References

Exploit 1

Patch 1

Advisory 4

Other 8

  • TI-2008-01097 Directory traversal vulnerability in WEBrick in Ruby 1.8 before 1.8.5-p115 and… CVSS 2.0MEDIUM 5.0
  • TI-2020-15633 An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through… CVSS 3.1HIGH 7.5
  • TI-2025-05843 Ruby WEBrick read_header HTTP Request Smuggling Vulnerability CVSS 3.1MEDIUM 5.9
  • TI-2019-08907 The WEBrick gem 1.4.2 for Ruby allows directory traversal if the attacker once had local… CVSS 3.0MEDIUM 5.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences