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Fencer Intel
high 7.5

CVE-2009-4492 in the critical feed json

WEBrick Improper Input Validation vulnerability

published 16y ago modified 4mo ago also EUVD-2017-0178 , GHSA-6mq2-37j5-w6r6

cvss
7.5
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
16.2%
EPSS 16.2% chance of exploitation in 30 days, percentile 96%
public exploits
1
Exploit-DB

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.

Patch / fix

  • rubygems webrick 1.4.0
  • ruby-lang ruby 1.8.6.388, 1.8.7.249, 1.9.1.378
  • ruby-lang webrick 1.4.0
  • ruby RHEL 5 1.8.5-19.el5_6.1
  • ruby-ri RHEL 5 1.8.5-19.el5_6.1
  • ruby-irb RHEL 5 1.8.5-19.el5_6.1
  • ruby-libs RHEL 5 1.8.5-19.el5_6.1
  • ruby-mode RHEL 5 1.8.5-19.el5_6.1
  • ruby-rdoc RHEL 5 1.8.5-19.el5_6.1
  • ruby-tcltk RHEL 5 1.8.5-19.el5_6.1
  • ruby RHEL 4 1.8.1-16.el4

red hat advisories RHSA-2011:0909RHSA-2011:0908

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2009-4492 updated cvss 2.6

ruby WEBrick log escape sequence

  • Red Hat Enterprise Linux (v. 5.6.z server) ruby 1.8.5-19.el5_6.1, ruby-ri 1.8.5-19.el5_6.1, ruby-irb 1.8.5-19.el5_6.1, ruby-libs 1.8.5-19.el5_6.1, ruby-mode 1.8.5-19.el5_6.1, ruby-rdoc 1.8.5-19.el5_6.1, +1 more
    fixed: vendor fix RHSA-2011:0909
  • Red Hat Enterprise Linux AS version 4 irb 1.8.1-16.el4, ruby 1.8.1-16.el4, ruby-libs 1.8.1-16.el4, ruby-mode 1.8.1-16.el4, ruby-tcltk 1.8.1-16.el4 Red Hat Enterprise Linux Desktop version 4 irb 1.8.1-16.el4, ruby 1.8.1-16.el4, ruby-libs 1.8.1-16.el4, ruby-mode 1.8.1-16.el4, ruby-tcltk 1.8.1-16.el4 Red Hat Enterprise Linux ES version 4 irb 1.8.1-16.el4, ruby 1.8.1-16.el4, ruby-libs 1.8.1-16.el4, ruby-mode 1.8.1-16.el4, ruby-tcltk 1.8.1-16.el4 Red Hat Enterprise Linux WS version 4 irb 1.8.1-16.el4, ruby 1.8.1-16.el4, ruby-libs 1.8.1-16.el4, ruby-mode 1.8.1-16.el4, ruby-tcltk 1.8.1-16.el4
    fixed: vendor fix RHSA-2011:0908

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. First public exploit (EDB-33489)
  2. Published

Exploit prediction

16.23% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-33489 Ruby 1.9.1 - WEBrick 'Terminal Escape Sequence in Logs' Command Injection remote, 2010-01-11
  • ush.it http://www.ush.it/team/ush/hack_httpd_escape/adv.txt referenced PoC, tagged "exploit" by a source, unverified
  • securityfocus.com http://www.securityfocus.com/bid/37710 referenced PoC, tagged "exploit" by a source, unverified
  • securitytracker.com http://securitytracker.com/id?1023429 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected packages

ecosystem package affected fixed in
rubygems webrick
<1.4.0
1.4.0

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Improved CPE configurations. This old version of WEBrick embedded in old ruby versions was not versioned properly, so just report the vuln as against ruby itself.