Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick i
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.
- Published
- Aug 12, 2008
- Updated
- Jun 16, 2026
- EPSS
- 70.2% · 99th percentile
- CWE
- CWE-399
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Report tools
Action score
52
Plan
Add it to your regular patch cycle.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 21 / 30 · 70.2%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| ruby-lang | ruby | cpe:2.3:a:ruby-lang:ruby |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- ruby-lang rubyup to 1.8.5 inclusive
- ruby-lang ruby1.6.8
- ruby-lang ruby1.8.0
- ruby-lang ruby1.8.1
- ruby-lang ruby1.8.2
- ruby-lang ruby1.8.3
- ruby-lang ruby1.8.4
- ruby-lang ruby1.8.5
- ruby-lang ruby1.8.6
- ruby-lang ruby1.8.7
- ruby-lang ruby1.9.0
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:4.0 | ruby1.8 | before 1.8.5-4etch3 | 1.8.5-4etch3 |
| Debian:4.0 | ruby1.9 | before 1.9.0+20060609-1etch3 | 1.9.0+20060609-1etch3 |
| Red Hat:enterprise_linux:4::as | irb | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:4::as | ruby | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:4::as | ruby-debuginfo | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:4::as | ruby-devel | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:4::as | ruby-docs | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:4::as | ruby-libs | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:4::as | ruby-mode | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:4::as | ruby-tcltk | before 0:1.8.1-7.el4_7.1 | 0:1.8.1-7.el4_7.1 |
| Red Hat:enterprise_linux:5::client | ruby-docs | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client | ruby-irb | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client | ruby-libs | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client | ruby-rdoc | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client | ruby-ri | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client | ruby-tcltk | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client_workstation | ruby | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client_workstation | ruby-debuginfo | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client_workstation | ruby-devel | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:enterprise_linux:5::client_workstation | ruby-mode | before 0:1.8.5-5.el5_2.5 | 0:1.8.5-5.el5_2.5 |
| Red Hat:hummingbird:1 | ruby3.3 | before 0:3.3.10-23.1.hum1 | 0:3.3.10-23.1.hum1 |
| Red Hat:hummingbird:1 | ruby3.3-default-gems | before 0:3.3.10-23.1.hum1 | 0:3.3.10-23.1.hum1 |
| Red Hat:hummingbird:1 | ruby3.4 | before 0:3.4.8-31.1.hum1 | 0:3.4.8-31.1.hum1 |
| Red Hat:hummingbird:1 | ruby3.4-default-gems | before 0:3.4.8-31.1.hum1 | 0:3.4.8-31.1.hum1 |
+2
Same product
ruby-lang: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-17405Ruby before 2.4.3 allows Net::FTP command injection.57Plan
- CVE-2021-28966In Ruby through 3.0 on Windows, a remote attacker can submit a crafted path when a Web application handles a parameter with TmpDir.47Plan
- CVE-2017-14064Ruby through 2.2.7, 2.3.x through 2.3.4, and 2.4.x through 2.4.1 can expose arbitrary memory during a JSON.generate call.42Plan
- CVE-2017-17790The lazy_initialize function in lib/resolv.rb in Ruby through 2.4.3 uses Kernel#open, which might allow Command Injection attacks, as demons41Plan
- CVE-2016-2339An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby.41Plan
- CVE-2016-2337Type confusion exists in _cancel_eval Ruby's TclTkIp class method.41Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Debian:ruby1.8 | 1.8.5-4etch3 · Debian:4.0 | Package registry (OSV) |
| Debian:ruby1.9 | 1.9.0+20060609-1etch3 · Debian:4.0 | Package registry (OSV) |
| Red Hat:irb | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby-debuginfo | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby-devel | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby-docs | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby-irb | 0:1.8.5-5.el5_2.5 · Red Hat:enterprise_linux:5::client | Package registry (OSV) |
| Red Hat:ruby-libs | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby-mode | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby-rdoc | 0:1.8.5-5.el5_2.5 · Red Hat:enterprise_linux:5::client | Package registry (OSV) |
| Red Hat:ruby-ri | 0:1.8.5-5.el5_2.5 · Red Hat:enterprise_linux:5::client | Package registry (OSV) |
| Red Hat:ruby-tcltk | 0:1.8.1-7.el4_7.1 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| Red Hat:ruby3.3 | 0:3.3.10-23.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Exploit-DB entry ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | dos | 2008-08-11 |
| Metasploit module | auxiliary/dos/http/webrick_regexRuby WEBrick::HTTP::DefaultFileHandler DoSauxiliary | 2008-08-08 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Metasploit-5 d
- First PoC-2 d
- Published
- TodaySep 30, 2026+6622 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- C · the service can be disrupted
- Attack complexity
- Low
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- C
Weakness class (CWE)
CWE-399 · Resource Management ErrorsCVSS vector
AV:N/AC:L/Au:N/C:N/I:N/A:C
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- bugs.debian.org/cgi-bin/bugreport.cgi?bug=494401
- lists.apple.com/archives/security-announce/2009/May/msg00002.html
- secunia.com/advisories/31430
- secunia.com/advisories/31697
- secunia.com/advisories/32165
- secunia.com/advisories/32219
- secunia.com/advisories/32255
- secunia.com/advisories/32256
- secunia.com/advisories/32371
- secunia.com/advisories/33178
- secunia.com/advisories/35074
- security.gentoo.org/glsa/glsa-200812-17.xml
- support.apple.com/kb/HT3549
- support.avaya.com/elmodocs2/security/ASA-2008-424.htm
- wiki.rpath.com/wiki/Advisories:rPSA-2008-0264
- www.debian.org/security/2008/dsa-1651
- www.debian.org/security/2008/dsa-1652
- www.redhat.com/support/errata/RHSA-2008-0897.html
- www.securityfocus.com/archive/1/495884/100/0/threaded
- www.securityfocus.com/bid/30644
Vendor advisories and official records. Exploit/PoC links are deliberately left out.