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.

DL::dlopen in Ruby 1.8, 1.9.0, 1.9.2, 1.9.3, 2.0.0 before patchlevel 648, and 2.1 before 2.1.8 opens libraries with tainted names.

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."

The REXML parser in Ruby 1.9.x before 1.9.3 patchlevel 551, 2.0.x before 2.0.0 patchlevel 598, and 2.1.x before 2.1.5 allows remote attackers to cause a denial of service (CPU and memory consumption) a crafted XML document containing an empty string in an entity that is used in a large number of nested entity references, aka an XML Entity Expansion (XEE) attack. NOTE: this vulnerability exists because of an incomplete fix for CVE-2013-1821 and CVE-2014-8080.

The REXML parser in Ruby 1.9.x before 1.9.3-p550, 2.0.x before 2.0.0-p594, and 2.1.x before 2.1.4 allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document, aka an XML Entity Expansion (XEE) attack.

Algorithmic complexity vulnerability in Gem::Version::ANCHORED_VERSION_PATTERN in lib/rubygems/version.rb in RubyGems before 1.8.23.2, 1.8.24 through 1.8.26, 2.0.x before 2.0.10, and 2.1.x before 2.1.5, as used in Ruby 1.9.0 through 2.0.0p247, allows remote attackers to cause a denial of service (CPU consumption) via a crafted gem version that triggers a large amount of backtracking in a regular expression. NOTE: this issue is due to an incomplete fix for CVE-2013-4287.