#ruby

Redcarpet is a Ruby library for Markdown processing. In Redcarpet before version 3.5.1, there is an injection vulnerability which can enable a cross-site scripting attack. In affected versions no HTML escaping was being performed when processing quotes. This applies even when the `:escape_html` option was being used. This is fixed in version 3.5.1 by the referenced commit.

Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. In Nokogiri before version 1.11.0.rc4 there is an XXE vulnerability. XML Schemas parsed by Nokogiri::XML::Schema are trusted by default, allowing external resources to be accessed over the network, potentially enabling XXE or SSRF attacks. This behavior is counter to the security policy followed by Nokogiri maintainers, which is to treat all input as untrusted by default whenever possible. This is fixed in Nokogiri version 1.11.0.rc4.

A spoofing issue existed in the handling of URLs. This issue was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.0.1, Safari 14.0.1. Visiting a malicious website may lead to address bar spoofing.

Grafana before 7.1.0-beta 1 allows XSS via a query alias for the ElasticSearch datasource.

Cure53 DOMPurify before 2.0.17 allows mutation XSS. This occurs because a serialize-parse roundtrip does not necessarily return the original DOM tree, and a namespace can change from HTML to MathML, as demonstrated by nesting of FORM elements.

An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through 2.7.1. WEBrick, a simple HTTP server bundled with Ruby, had not checked the transfer-encoding header value rigorously. An attacker may potentially exploit this issue to bypass a reverse proxy (which also has a poor header check), which may lead to an HTTP Request Smuggling attack.

An issue was discovered in the gon gem before gon-6.4.0 for Ruby. MultiJson does not honor the escape_mode parameter to escape fields as an XSS protection mechanism. To mitigate, json_dumper.rb in gon now does escaping for XSS by default without relying on MultiJson.

The kramdown gem before 2.3.0 for Ruby processes the template option inside Kramdown documents by default, which allows unintended read access (such as template="/etc/passwd") or unintended embedded Ruby code execution (such as a string that begins with template="string://<%= `). NOTE: kramdown is used in Jekyll, GitLab Pages, GitHub Pages, and Thredded Forum.

A directory traversal vulnerability exists in rack < 2.2.0 that allows an attacker perform directory traversal vulnerability in the Rack::Directory app that is bundled with Rack which could result in information disclosure.

A deserialization of untrusted data vulnernerability exists in rails < 5.2.4.3, rails < 6.0.3.1 that can allow an attacker to unmarshal user-provided objects in MemCacheStore and RedisCacheStore potentially resulting in an RCE.