CVE-2019-16782

There's a possible information leak / session hijack vulnerability in Rack (RubyGem rack). This vulnerability is patched in versions 1.6.12 and 2.0.8. Attackers may be able to find and hijack sessions by using timing attacks targeting the session id. Session ids are usually stored and indexed in a database that uses some kind of scheme for speeding up lookups of that session id. By carefully measuring the amount of time it takes to look up a session, an attacker may be able to find a valid session id and hijack the session. The session id itself may be generated randomly, but the way the session is indexed by the backing store does not use a secure comparison.

• CWE-208
• CWE-203

• http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00016.htmlThird Party Advisory
• http://www.openwall.com/lists/oss-security/2019/12/18/2Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2019/12/18/3Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2019/12/19/3Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2020/04/08/1Mailing List, Patch, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2020/04/09/2Mailing List, Third Party Advisory
• https://github.com/rack/rack/commit/7fecaee81f59926b6e1913511c90650e76673b38Patch, Third Party Advisory
• https://github.com/rack/rack/security/advisories/GHSA-hrqr-hxpp-chr3Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HZXMWILCICQLA2BYSP6I2CRMUG53YBLX/
• http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00016.htmlThird Party Advisory
• http://www.openwall.com/lists/oss-security/2019/12/18/2Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2019/12/18/3Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2019/12/19/3Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2020/04/08/1Mailing List, Patch, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2020/04/09/2Mailing List, Third Party Advisory
• https://github.com/rack/rack/commit/7fecaee81f59926b6e1913511c90650e76673b38Patch, Third Party Advisory
• https://github.com/rack/rack/security/advisories/GHSA-hrqr-hxpp-chr3Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HZXMWILCICQLA2BYSP6I2CRMUG53YBLX/

Published

Dec 18, 2019

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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