Home/CVE/Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFile
CVE

CVE-2008-3656

Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFile

Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted HTTP request that is processed by a backtracking regular expression.

HIGH · CVSS 7.8 EPSS 0.7933
Act now
  • EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
  • EPSS percentile: top 1% of all CVEs by exploitation likelihood
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules3 YARA rules0
▤

Affected Products & Versions

2
ruby-lang ruby<= 1.8.5
ruby-lang rubyall versions
⚠

Public Exploits & PoCs

2
dosRuby 1.9 - 'WEBrick::HTTP::DefaultFileHandler' Crafted HTTP Request Denial of Serviceverified
pocwww.ruby-lang.org · multiple-vulnerabilities-in-rubywww.ruby-lang.org
◈

Sigma Hunt Rules

3
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
productmediumRuby on Rails Framework Exceptions
productmediumPotential Ruby Reverse Shell
productmediumRuby Inline Command Execution
▣

Scoring & Timeline

7.8
HIGH · CVSS v2 (legacy) · cve@mitre.org
View on NVD
This CVE predates CVSS v3; the legacy v2 score is shown so triage still has a severity to work with.
v2 Vector
AV:N/AC:L/Au:N/C:N/I:N/A:C
Published to NVD13 Aug 2008 · 01:41 AM
⚑

Vendor Advisories

6
rhsaRHSA-2026:7307Moderate
rhsaRHSA-2026:8838Moderate
rhsaRHSA-2026:7305Moderate
rhsaRHSA-2008:0981Moderate
usnUSN-651-1
🔗

References & Sources

29
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=494401
http://lists.apple.com/archives/security-announce/2009/May/msg00002.html
http://secunia.com/advisories/31430
http://secunia.com/advisories/31697
http://secunia.com/advisories/32165
http://secunia.com/advisories/32219
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