---
title: "CVE-2008-3656: Algorithmic complexity vulnerability… | CubePath"
description: "Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5…"
language: en
source: https://cubepath.com/security/cve/CVE-2008-3656
---

# CVE-2008-3656: Algorithmic complexity vulnerability… | CubePath

## Description

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.

Official description from the CVE record, published by mitre. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2008-3656)

## Key data

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.70202 (70.2% probability)

Percentile

99.4%

Scores of

Nov 10, 2026

Model

v2026.06.15

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [oval:org.mitre.oval:def:9682](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9682)  (oval.cisecurity.org) vdb-entry signature
- [31430](http://secunia.com/advisories/31430)  (secunia.com) third-party-advisory
- [31697](http://secunia.com/advisories/31697)  (secunia.com) third-party-advisory
- [USN-651-1](https://usn.ubuntu.com/651-1/)  (usn.ubuntu.com) vendor-advisory
- [ruby-webrick-dos(44371)](https://exchange.xforce.ibmcloud.com/vulnerabilities/44371)  (exchange.xforce.ibmcloud.com) vdb-entry
- [support.apple.com/kb/HT3549](http://support.apple.com/kb/HT3549)
- [wiki.rpath.com/wiki/Advisories:rPSA-2008-0264](http://wiki.rpath.com/wiki/Advisories:rPSA-2008-0264)
- [DSA-1652](http://www.debian.org/security/2008/dsa-1652)  (debian.org) vendor-advisory
- [FEDORA-2008-8736](https://www.redhat.com/archives/fedora-package-announce/2008-October/msg00299.html)  (redhat.com) vendor-advisory
- [35074](http://secunia.com/advisories/35074)  (secunia.com) third-party-advisory
- [support.avaya.com/elmodocs2/security/ASA-2008-424.htm](http://support.avaya.com/elmodocs2/security/ASA-2008-424.htm)
- [DSA-1651](http://www.debian.org/security/2008/dsa-1651)  (debian.org) vendor-advisory
- [APPLE-SA-2009-05-12](http://lists.apple.com/archives/security-announce/2009/May/msg00002.html)  (lists.apple.com) vendor-advisory
- [30644](http://www.securityfocus.com/bid/30644)  (securityfocus.com) vdb-entry
- [RHSA-2008:0897](http://www.redhat.com/support/errata/RHSA-2008-0897.html)  (redhat.com) vendor-advisory
- [ruby-lang.org/en/news/2008/08/08/multiple-vulnerabilities-i…](http://www.ruby-lang.org/en/news/2008/08/08/multiple-vulnerabilities-in-ruby/)
- [32219](http://secunia.com/advisories/32219)  (secunia.com) third-party-advisory
- [1020654](http://www.securitytracker.com/id?1020654)  (securitytracker.com) vdb-entry
- [TA09-133A](http://www.us-cert.gov/cas/techalerts/TA09-133A.html)  (us-cert.gov) third-party-advisory
- [32255](http://secunia.com/advisories/32255)  (secunia.com) third-party-advisory
- [ADV-2009-1297](http://www.vupen.com/english/advisories/2009/1297)  (vupen.com) vdb-entry
- [20080831 rPSA-2008-0264-1 ruby](http://www.securityfocus.com/archive/1/495884/100/0/threaded)  (securityfocus.com) mailing-list
- [32371](http://secunia.com/advisories/32371)  (secunia.com) third-party-advisory
- [32165](http://secunia.com/advisories/32165)  (secunia.com) third-party-advisory
- [GLSA-200812-17](http://security.gentoo.org/glsa/glsa-200812-17.xml)  (security.gentoo.org) vendor-advisory
- [33178](http://secunia.com/advisories/33178)  (secunia.com) third-party-advisory
- [ADV-2008-2334](http://www.vupen.com/english/advisories/2008/2334)  (vupen.com) vdb-entry
- [FEDORA-2008-8738](https://www.redhat.com/archives/fedora-package-announce/2008-October/msg00259.html)  (redhat.com) vendor-advisory
- [bugs.debian.org/cgi-bin/bugreport.cgi?bug=494401](http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=494401)
- [32256](http://secunia.com/advisories/32256)  (secunia.com) third-party-advisory

## Timeline

1. ID reserved Aug 12, 2008
2. Record published Aug 13, 2008
3. Record last updated Aug 7, 2024

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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:59 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)