CVE-2025-27220

A flaw was found in Ruby's CGI gem. The CGI::Util#escapeElement method is vulnerable to Regular expression Denial of Service (ReDoS), allowing a specially crafted input to cause a high CPU consumption.

It was discovered that Ruby incorrectly handled parsing of an XML document that has specific XML characters in an attribute value using REXML gem. An attacker could use this issue to cause Ruby to crash, resulting in a denial of service. This issue only affected in Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 24.10. It was discovered that Ruby incorrectly handled expanding ranges in the net-imap response parser. If a user or automated system were tricked into connecting to a malicious IMAP server, a remote attacker could possibly use this issue to consume memory, leading to a denial of service. This issue only affected Ubuntu 24.04 LTS, and Ubuntu 24.10.