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.

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.

Type confusion exists in two methods of Ruby's WIN32OLE class, ole_invoke and ole_query_interface. Attacker passing different type of object than this assumed by developers can cause arbitrary code execution.

Type confusion exists in _cancel_eval Ruby's TclTkIp class method. Attacker passing different type of object than String as "retval" argument can cause arbitrary code execution.

An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby. In Fiddle::Function.new "initialize" heap buffer "arg_types" allocation is made based on args array length. Specially constructed object passed as element of args array can increase this array size after mentioned allocation and cause heap overflow.

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.