REXML is an XML toolkit for Ruby. The REXML gem before 3.3.2 has some DoS vulnerabilities when it parses an XML that has many specific characters such as whitespace character, `>]` and `]>`. The REXML gem 3.3.3 or later include the patches to fix these vulnerabilities.
A vulnerability was found in REXML, an XML toolkit used for Ruby. When parsing an untrusted XML with many specific characters, the REXML gem may take a long time, leading to a denial of service condition. Some of these special characters include the whitespace character, '>]', and ']>'.
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.
