Heap-based buffer overflow in the rbstrjustify function in string.c in Ruby 1.9.1 before 1.9.1-p376 allows context-dependent attackers to execute arbitrary code via unspecified vectors involving (1) String#ljust, (2) String#center, or (3) String#rjust. NOTE: some of these details are obtained from third party information.

Multiple integer overflows in the rbarystore function in Ruby 1.8.4 and earlier, 1.8.5 before 1.8.5-p231, 1.8.6 before 1.8.6-p230, and 1.8.7 before 1.8.7-p22 allow context-dependent attackers to execute arbitrary code or cause a denial of service via unknown vectors, a different issue than CVE-2008-2662, CVE-2008-2664, and CVE-2008-2725. NOTE: as of 20080624, there has been inconsistent usage of multiple CVE identifiers related to Ruby. The CVE description should be regarded as authoritative, although it is likely to change.

Multiple integer overflows in the rbstrbufappend function in Ruby 1.8.4 and earlier, 1.8.5 before 1.8.5-p231, 1.8.6 before 1.8.6-p230, 1.8.7 before 1.8.7-p22, and 1.9.0 before 1.9.0-2 allow context-dependent attackers to execute arbitrary code or cause a denial of service via unknown vectors that trigger memory corruption, a different issue than CVE-2008-2663, CVE-2008-2664, and CVE-2008-2725. NOTE: as of 20080624, there has been inconsistent usage of multiple CVE identifiers related to Ruby. This CVE description should be regarded as authoritative, although it is likely to change.

converter.rb in the md2pdf gem 0.0.1 for Ruby allows context-dependent attackers to execute arbitrary commands via shell metacharacters in a filename.

A double free was found in the Regexp compiler in Ruby 3.x before 3.0.4 and 3.1.x before 3.1.2. If a victim attempts to create a Regexp from untrusted user input, an attacker may be able to write to unexpected memory locations.

An instance of OpenSSL::X509::Name contains entities such as CN, C and so on. Some two instances of OpenSSL::X509::Name are equal only when all entities are exactly equal. However, there is a bug that the equality check is not correct if the value of an entity of the argument (right-hand side) starts with the value of the receiver (left-hand side). So, if a malicious X.509 certificate is passed to compare with an existing certificate, there is a possibility to be judged incorrectly that they are equal.

External References:

https://www.ruby-lang.org/en/news/2018/10/17/openssl-x509-name-equality-check-does-not-work-correctly-cve-2018-16395/

A buffer overrun vulnerability was discovered in CGI.escapehtml. This can lead to a buffer overflow when a user passes a very large string (> 700 MB) to CGI.escapehtml on a platform where long type takes 4 bytes, typically, Windows.

Last updated 24 July 2024

An exploitable heap overflow vulnerability exists in the Fiddle::Function.new "initialize" function functionality of Ruby. In Fiddle::Function.new "initialize" heap buffer "argtypes" 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 OpenSSL extension of Ruby (Git trunk) versions after 2011-09-01 up to 2011-11-03 always generated an exponent value of '1' to be used for private RSA key generation. A remote attacker could use this flaw to bypass or corrupt integrity of services, depending on strong private RSA keys generation mechanism.

The parseryyerror function in the UTF-8 parser in Ruby 2.4.1 allows attackers to cause a denial of service (invalid write or read) or possibly have unspecified other impact via a crafted Ruby script, related to the parsertokaddutf8 function in parse.y. NOTE: this might have security relevance as a bypass of a $SAFE protection mechanism.

An issue was discovered in Oniguruma 6.2.0, as used in Oniguruma-mod in Ruby through 2.4.1 and mbstring in PHP through 7.1.5. A stack out-of-bounds write in onigencunicodegetcasefoldcodesbystr() occurs during regular expression compilation. Code point 0xFFFFFFFF is not properly handled in unicodeunfoldkey(). A malformed regular expression could result in 4 bytes being written off the end of a stack buffer of expandcasefoldstring() during the call to onigencunicodegetcasefoldcodesbystr(), a typical stack buffer overflow.

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

Last updated 25 August 2025

Last updated 25 August 2025

An exploitable heap overflow vulnerability exists in the Psych::Emitter startdocument function of Ruby. In Psych::Emitter startdocument 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.

kelredd-pruview gem 0.3.8 for Ruby allows context-dependent attackers to execute arbitrary commands via shell metacharacters in a filename argument to (1) document.rb, (2) video.rb, or (3) videoimage.rb.

It was discovered that the Net::FTP module did not properly process filenames in combination with certain operations. A remote attacker could exploit this flaw to execute arbitrary commands by setting up a malicious FTP server and tricking a user or Ruby application into downloading files with specially crafted names using the Net::FTP module.

Last updated 25 August 2025

The extractfromocr function in lib/docsplit/textextractor.rb in the Karteek Docsplit (karteek-docsplit) gem 0.5.4 for Ruby allows context-dependent attackers to execute arbitrary commands via shell metacharacters in a PDF filename.

Dir.open, Dir.new, Dir.entries and Dir.empty? accept the path of the target directory as their parameter. If the parameter contains NUL (\0) bytes, these methods recognize that the path is completed before the NUL bytes. So, if a script accepts an external input as the argument of these methods, the attacker can make the unintentional directory traversal.

Affected versions:

Ruby 2.2 series: 2.2.9 and earlier Ruby 2.3 series: 2.3.6 and earlier Ruby 2.4 series: 2.4.3 and earlier Ruby 2.5 series: 2.5.0 and earlier

External References:

https://www.ruby-lang.org/en/news/2018/03/28/poisoned-nul-byte-dir-cve-2018-8780/

Last updated 25 August 2025

A vulnerability was found in Ruby that allows HTTP header injection. A CGI application using the CGI library may insert untrusted input into the HTTP response header. This issue can allow an attacker to insert a newline character to split a header and inject malicious content to deceive clients.

DL::dlopen could open a library with tainted library name even if $SAFE > 0. This vulnerability affects Ruby versions 1.8, 1.9, 2.1, 2.2.

Upstream patch: https://github.com/ruby/ruby/commit/4600cf725a86ce31266153647ae5aa1197b1215b

Additional information and CVE assignment:

http://seclists.org/oss-sec/2015/q3/222

Impact

A format string injection vulnerability than that lead to denial of service attacks or information disclosure, when the allowduplicatekey: false parsing option is used to parse user supplied documents.

This option isn't the default, if you didn't opt-in to use it, you are not impacted.

Patches

Patched in 2.19.2.

Workarounds

The issue can be avoided by not using the allowduplicatekey: false parsing option.

An issue was discovered in Ruby 4 before 4.0.5. A race condition leading to a use-after-free in the pthread-based getaddrinfo timeout handler (rbgetaddrinfo in ext/socket/raddrinfo.c) allows a remote attacker who can delay DNS responses near the user-specified timeout to crash a Ruby process that calls Addrinfo.getaddrinfo(..., timeout:) or Socket.tcp(..., resolvtimeout:). Memory-corruption-based exploitation is theoretically possible. The attack could, for example, be carried out through a crafted authoritative DNS server or recursive resolver.

An issue was discovered in Ruby before 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3. It does not taint strings that result from unpacking tainted strings with some formats.

Last updated 11 July 2025

Last updated 11 July 2025

Ruby (aka CRuby) before 1.8.7-p357 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table.