An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS command, aka a "StartTLS stripping attack."

In RDoc 3.11 through 6.x before 6.3.1, as distributed with Ruby through 3.0.1, it is possible to execute arbitrary code via | and tags in a filename.

REXML is an XML toolkit for Ruby. The REXML gem before 3.3.9 has a ReDoS vulnerability when it parses an XML that has many digits between &# and x...; in a hex numeric character reference (&#x...;). This does not happen with Ruby 3.2 or later. Ruby 3.1 is the only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

REXML is an XML toolkit for Ruby. The REXML gem 3.3.2 has a DoS vulnerability when it parses an XML that has many entity expansions with SAX2 or pull parser API. The REXML gem 3.3.3 or later include the patch to fix the vulnerability.

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 ReDoS issue was discovered in the URI component before 0.12.2 for Ruby. The URI parser mishandles invalid URLs that have specific characters. There is an increase in execution time for parsing strings to URI objects with rfc2396_parser.rb and rfc3986_parser.rb. NOTE: this issue exists becuse of an incomplete fix for CVE-2023-28755. Version 0.10.3 is also a fixed version.

A ReDoS issue was discovered in the Time component through 0.2.1 in Ruby through 3.2.1. The Time parser mishandles invalid URLs that have specific characters. It causes an increase in execution time for parsing strings to Time objects. The fixed versions are 0.1.1 and 0.2.2.

A ReDoS issue was discovered in the URI component through 0.12.0 in Ruby through 3.2.1. The URI parser mishandles invalid URLs that have specific characters. It causes an increase in execution time for parsing strings to URI objects. The fixed versions are 0.12.1, 0.11.1, 0.10.2 and 0.10.0.1.

The cgi gem before 0.1.0.2, 0.2.x before 0.2.2, and 0.3.x before 0.3.5 for Ruby allows HTTP response splitting. This is relevant to applications that use untrusted user input either to generate an HTTP response or to create a CGI::Cookie object.

An exploitable heap overflow vulnerability exists in the Psych::Emitter start_document function of Ruby. In Psych::Emitter start_document function heap buffer "head" allocation is made based on tags array length. Specially constructed object passed as element of tags array can increase this array size after mentioned allocation and cause heap overflow.