What’s Vulnerable › Vulnerabilities

CVE-2013-0156

• Severity: high (CVSS 7.5 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 99.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2013-01-13 · updated 2026-06-16
• Weakness: CWE-20

Description

active_support/core_ext/hash/conversions.rb in Ruby on Rails before 2.3.15, 3.0.x before 3.0.19, 3.1.x before 3.1.10, and 3.2.x before 3.2.11 does not properly restrict casts of string values, which allows remote attackers to conduct object-injection attacks and execute arbitrary code, or cause a denial of service (memory and CPU consumption) involving nested XML entity references, by leveraging Action Pack support for (1) YAML type conversion or (2) Symbol type conversion.

Affected products

• Debian Linux: 6.0, 7.0
• Ruby on Rails: from 3.2.0 before 3.2.11 — fixed in 3.2.11
• rubyonrails Ruby On Rails: before 2.3.15; from 3.0.0 before 3.0.19; from 3.1.0 before 3.1.10 — fixed in 2.3.15, 3.0.19, 3.1.10

How to fix

Upgrade to a fixed version: Ruby on Rails 3.2.11; rubyonrails Ruby On Rails 2.3.15, 3.0.19, 3.1.10. Check the vendor advisory for mitigations.

References

• http://ics-cert.us-cert.gov/advisories/ICSA-13-036-01A
• http://lists.apple.com/archives/security-announce/2013/Mar/msg00002.html
• http://rhn.redhat.com/errata/RHSA-2013-0153.html
• http://rhn.redhat.com/errata/RHSA-2013-0154.html
• http://rhn.redhat.com/errata/RHSA-2013-0155.html
• http://weblog.rubyonrails.org/2013/1/28/Rails-3-0-20-and-2-3-16-have-been-released/
• http://www.debian.org/security/2013/dsa-2604
• http://www.fujitsu.com/global/support/software/security/products-f/sw-sv-rcve-ror201301e.html
• http://www.insinuator.net/2013/01/rails-yaml/
• http://www.kb.cert.org/vuls/id/380039
• http://www.kb.cert.org/vuls/id/628463
• https://community.rapid7.com/community/metasploit/blog/2013/01/09/serialization-mischief-in-ruby-land-cve-2013-0156

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