USN-7709-1: WEBrick vulnerability

USN-7709-1: WEBrick vulnerability
Publication date: 21 August 2025
Overview : WEBrick could allow an HTTP request smuggling attack.
Releases:

Packages

• ruby-webrick - HTTP server toolkit in Ruby

Details
It was discovered that WEBrick incorrectly parsed HTTP headers. In
configurations where WEBrick is placed behind an HTTP proxy, a remote
attacker could possibly use this issue to perform an HTTP Request Smuggling
attack.

Update instructions
The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version

• 25.04 plucky: ruby-webrick – 1.8.1-1ubuntu1.1
• 24.04 noble: ruby-webrick – 1.8.1-1ubuntu0.2
• 22.04 jammy: ruby-webrick – 1.7.0-3ubuntu0.2