CVE-2019-16782
There's a possible information leak / session hijack vulnerability in Rack (RubyGem rack).
Does this matter?
Lower severity and a low EPSS score (3.70%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 3.70% probability · 90th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-208, CWE-203
- Affected
- rack/rack · fedoraproject/fedora · opensuse/leap
- Source
- security-advisories@github.com
EPSS 3.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- 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/
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.