The ruby-openid gem before 2.2.2 for Ruby allows remote OpenID providers to cause a denial of service (CPU consumption) via (1) a large XRDS document or (2) an XML Entity Expansion (XEE) attack.

References

• https://nvd.nist.gov/vuln/detail/CVE-2013-1812
• openid/ruby-openid#43
• openid/ruby-openid@a3693ce
• https://bugzilla.redhat.com/show_bug.cgi?id=918134
• GHSA-6c8p-qphv-668v
• https://github.com/openid/ruby-openid/blob/master/CHANGELOG.md
• http://lists.fedoraproject.org/pipermail/package-announce/2013-November/120204.html
• http://lists.fedoraproject.org/pipermail/package-announce/2013-November/120361.html
• http://www.openwall.com/lists/oss-security/2013/03/03/8
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-openid/CVE-2013-1812.yml