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.

Off-by-one error in the encodes function in pack.c in Ruby 1.9.3 and earlier, and 2.x through 2.1.2, when using certain format string specifiers, allows context-dependent attackers to cause a denial of service (segmentation fault) via vectors that trigger a stack-based buffer overflow.

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.

The OpenSSL::SSL.verify_certificate_identity function in lib/openssl/ssl.rb in Ruby 1.8 before 1.8.7-p374, 1.9 before 1.9.3-p448, and 2.0 before 2.0.0-p247 does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

The safe-level feature in Ruby 1.8.7 allows context-dependent attackers to modify strings via the NameError#to_s method when operating on Ruby objects. NOTE: this issue is due to an incomplete fix for CVE-2011-1005.

Ruby 1.8.7 before patchlevel 371, 1.9.3 before patchlevel 286, and 2.0 before revision r37068 allows context-dependent attackers to bypass safe-level restrictions and modify untainted strings via the name_err_mesg_to_str API function, which marks the string as tainted, a different vulnerability than CVE-2011-1005.

lib/rexml/text.rb in the REXML parser in Ruby before 1.9.3-p392 allows remote attackers to cause a denial of service (memory consumption and crash) via crafted text nodes in an XML document, aka an XML Entity Expansion (XEE) attack.

Ruby (aka CRuby) 1.9 before 1.9.3-p327 and 2.0 before r37575 computes hash values without properly 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, as demonstrated by a universal multicollision attack against a variant of the MurmurHash2 algorithm, a different vulnerability than CVE-2011-4815.

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.

The SecureRandom.random_bytes function in lib/securerandom.rb in Ruby before 1.8.7-p352 and 1.9.x before 1.9.2-p290 relies on PID values for initialization, which makes it easier for context-dependent attackers to predict the result string by leveraging knowledge of random strings obtained in an earlier process with the same PID.

Ruby before 1.8.7-p352 does not reset the random seed upon forking, which makes it easier for context-dependent attackers to predict the values of random numbers by leveraging knowledge of the number sequence obtained in a different child process, a related issue to CVE-2003-0900. NOTE: this issue exists because of a regression during Ruby 1.8.6 development.

The VpMemAlloc function in bigdecimal.c in the BigDecimal class in Ruby 1.9.2-p136 and earlier, as used on Apple Mac OS X before 10.6.7 and other platforms, does not properly allocate memory, which allows context-dependent attackers to execute arbitrary code or cause a denial of service (application crash) via vectors involving creation of a large BigDecimal value within a 64-bit process, related to an "integer truncation issue."

The safe-level feature in Ruby 1.8.6 through 1.8.6-420, 1.8.7 through 1.8.7-330, and 1.8.8dev allows context-dependent attackers to modify strings via the Exception#to_s method, as demonstrated by changing an intended pathname.

The FileUtils.remove_entry_secure method in Ruby 1.8.6 through 1.8.6-420, 1.8.7 through 1.8.7-330, 1.8.8dev, 1.9.1 through 1.9.1-430, 1.9.2 through 1.9.2-136, and 1.9.3dev allows local users to delete arbitrary files via a symlink attack.

WEBrick 1.3.1 in Ruby 1.8.6 through patchlevel 383, 1.8.7 through patchlevel 248, 1.8.8dev, 1.9.1 through patchlevel 376, and 1.9.2dev writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to modify a window's title, or possibly execute arbitrary commands or overwrite files, via an HTTP request containing an escape sequence for a terminal emulator.

The BigDecimal library in Ruby 1.8.6 before p369 and 1.8.7 before p173 allows context-dependent attackers to cause a denial of service (application crash) via a string argument that represents a large number, as demonstrated by an attempted conversion to the Float data type.

resolv.rb in Ruby 1.8.5 and earlier, 1.8.6 before 1.8.6-p287, 1.8.7 before 1.8.7-p72, and 1.9 r18423 and earlier uses sequential transaction IDs and constant source ports for DNS requests, which makes it easier for remote attackers to spoof DNS responses, a different vulnerability than CVE-2008-1447.

The REXML module in Ruby 1.8.6 through 1.8.6-p287, 1.8.7 through 1.8.7-p72, and 1.9 allows context-dependent attackers to cause a denial of service (CPU consumption) via an XML document with recursively nested entities, aka an "XML entity explosion."

The regular expression engine (regex.c) in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows remote attackers to cause a denial of service (infinite loop and crash) via multiple long requests to a Ruby socket, related to memory allocation failure, and as demonstrated against Webrick.

Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 does not properly restrict access to critical variables and methods at various safe levels, which allows context-dependent attackers to bypass intended access restrictions via (1) untrace_var, (2) $PROGRAM_NAME, and (3) syslog at safe level 4, and (4) insecure methods at safe levels 1 through 3.