Inconsistent interpretation of HTTP requests in WEBrick - CVE-2025-6442

Vulnerability identifier: #VU114416

CSH Severity: Medium

CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-6442

CWE-ID: CWE-444

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform HTTP request smuggling attacks.

The vulnerability exists due to improper validation of HTTP requests within the read_header() method. A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.

WEBrick
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP3
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Manager Proxy
SUSE Manager Retail Branch Server
SUSE Manager Server
SUSE Enterprise Storage
macOS
Basesystem Module
openSUSE Leap
Ubuntu
openEuler
Astronomer with IBM
watsonx.data
IBM Watson Discovery for IBM Cloud Pak for Data
rubygem-net-telnet
rubygem-xmlrpc
rubygem-io-console
rubygem-power_assert
rubygem-did_you_mean
rubygem-bigdecimal
ruby-webrick (Ubuntu package)
rubygem-json
rubygem-openssl
ruby2.3 (Ubuntu package)
ruby-debuginfo
ruby
ruby-debugsource
ruby-devel
ruby-help
ruby-irb
libruby2_5-2_5
ruby2.5-debugsource
ruby2.5-debuginfo
libruby2_5-2_5-debuginfo
ruby2.5-stdlib-debuginfo
ruby2.5
ruby2.5-stdlib
ruby2.5-devel-extra
ruby2.5-devel
ruby2.5-doc-ri
ruby2.5-doc
rubygems
rubygems-devel
rubygem-psych
rubygem-test-unit
rubygem-minitest
rubygem-rdoc
rubygem-rake

Install updates from vendor's website.

WEBrick - update to 1.8.2
Astronomer with IBM - update to 1.0.1
watsonx.data - update to 2.3.1
IBM Watson Discovery for IBM Cloud Pak for Data - update to 5.2.1
macOS - addressed in versions 14.8.2 23J126, 15.7.2 24G325, 26.1 25B78
rubygem-net-telnet - update to 0.1.1-135
rubygem-xmlrpc - update to 0.3.0-135
rubygem-io-console - update to 0.4.6-135
rubygem-power_assert - update to 1.1.1-135
rubygem-did_you_mean - update to 1.2.0-135
rubygem-bigdecimal - update to 1.3.4-135
ruby-webrick (Ubuntu package) - addressed in versions 1.7.0-3ubuntu0.2, 1.8.1-1ubuntu0.2, 1.8.1-1ubuntu1.1
rubygem-json - update to 2.1.0-135
rubygem-openssl - update to 2.1.2-135
ruby2.3 (Ubuntu package) - addressed in versions 2.3.1-2~ubuntu16.04.16+esm11, 2.5.1-1ubuntu1.16+esm6, 2.7.0-5ubuntu1.18+esm3
ruby-debuginfo - update to 2.5.8-135
ruby - update to 2.5.8-135
ruby-debugsource - update to 2.5.8-135
ruby-devel - update to 2.5.8-135
ruby-help - update to 2.5.8-135
ruby-irb - update to 2.5.8-135
libruby2_5-2_5 - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5-debugsource - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5-debuginfo - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
libruby2_5-2_5-debuginfo - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5-stdlib-debuginfo - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5 - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5-stdlib - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5-devel-extra - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5-devel - addressed in versions 2.5.9-150000.4.46.1, 2.5.9-150700.24.3.1
ruby2.5-doc-ri - update to 2.5.9-150000.4.46.1
ruby2.5-doc - update to 2.5.9-150000.4.46.1
rubygems - update to 2.7.6-135
rubygems-devel - update to 2.7.6-135
rubygem-psych - update to 3.0.2-135
rubygem-test-unit - update to 3.2.7-135
rubygem-minitest - update to 5.10.3-135
rubygem-rdoc - update to 6.0.1.1-135
rubygem-rake - update to 12.3.0-135

• https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
• https://www.zerodayinitiative.com/advisories/ZDI-25-414/

• HTTP request smuggling in WEBrick toolkit
• openEuler 20.03 LTS SP4 update for ruby
• SUSE update for ruby2.5
• Ubuntu update for ruby-webrick
• SUSE update for ruby2.5
• Astronomer with IBM update for Ruby WEBrick
• IBM Watson Discovery update for Ruby WEBrick
• Ubuntu update for ruby2.3
• Multiple vulnerabilities in Apple macOS Tahoe
• Multiple vulnerabilities in macOS Sequoia
• Multiple vulnerabilities in Apple macOS Sonoma
• SUSE update for ruby2.5
• IBM watsonx.data update for Ruby WEBrick