The Recurly Client Ruby Library before 2.0.13, 2.1.11, 2.2.5, 2.3.10, 2.4.11, 2.5.4, 2.6.3, 2.7.8, 2.8.2, 2.9.2, 2.10.4, 2.11.3 is vulnerable to a Server-Side Request Forgery vulnerability in the "Resource#find" method that could result in compromise of API keys or other critical resources.

The decode method in the OpenSSL::ASN1 module in Ruby before 2.2.8, 2.3.x before 2.3.5, and 2.4.x through 2.4.1 allows attackers to cause a denial of service (interpreter crash) via a crafted string.

Ruby before 2.4.2, 2.3.5, and 2.2.8 is vulnerable to a malicious format string which contains a precious specifier (*) with a huge minus value. Such situation can lead to a buffer overrun, resulting in a heap memory corruption or an information disclosure from the heap.

The Fiddle::Handle implementation in ext/fiddle/handle.c in Ruby before 2.0.0-p648, 2.1 before 2.1.8, and 2.2 before 2.2.4, as distributed in Apple OS X before 10.11.4 and other products, mishandles tainting, which allows context-dependent attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted string, related to the DL module and the libffi library. NOTE: this vulnerability exists because of a CVE-2009-5147 regression.

RubyGems 2.0.x before 2.0.16, 2.2.x before 2.2.4, and 2.4.x before 2.4.7 does not validate the hostname when fetching gems or making API requests, which allows remote attackers to redirect requests to arbitrary domains via a crafted DNS SRV record, aka a "DNS hijack attack."

SQL injection vulnerability in activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb in the PostgreSQL adapter for Active Record in Ruby on Rails 2.x and 3.x before 3.2.19 allows remote attackers to execute arbitrary SQL commands by leveraging improper bitstring quoting.

Multiple cross-site scripting (XSS) vulnerabilities in actionview/lib/action_view/helpers/number_helper.rb in Ruby on Rails before 3.2.17, 4.0.x before 4.0.3, and 4.1.x before 4.1.0.beta2 allow remote attackers to inject arbitrary web script or HTML via the (1) format, (2) negative_format, or (3) units parameter to the (a) number_to_currency, (b) number_to_percentage, or (c) number_to_human helper.

The ruby-openid gem before 2.2.2 for Ruby allows remote OpenID providers to cause a denial of service (CPU consumption) via (1) a large XRDS document or (2) an XML Entity Expansion (XEE) attack.

The sanitize_css method in lib/action_controller/vendor/html-scanner/html/sanitizer.rb in the Action Pack component in Ruby on Rails before 2.3.18, 3.0.x and 3.1.x before 3.1.12, and 3.2.x before 3.2.13 does not properly handle \n (newline) characters, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via crafted Cascading Style Sheets (CSS) token sequences.

The sanitize helper in lib/action_controller/vendor/html-scanner/html/sanitizer.rb in the Action Pack component in Ruby on Rails before 2.3.18, 3.0.x and 3.1.x before 3.1.12, and 3.2.x before 3.2.13 does not properly handle encoded : (colon) characters in URLs, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted scheme name, as demonstrated by including a : sequence.