Exim Mail Transfer Agent (MTA) Improper Input Validation

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-01-10
• EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official description

A flaw was found in Exim versions 4.87 to 4.91 (inclusive). Improper validation of recipient address in deliver_message() function in /src/deliver.c may lead to remote command execution.

CISA: Improper validation of recipient address in deliver_message() function in /src/deliver.c may lead to remote command execution.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 10 Jul 2022): Apply updates per vendor instructions.

• Patch on openwall.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ References ]References

• lists.opensuse.org/opensuse-security-announce/2019-06/msg00020.htmlMailing ListThird Party Advisory
• packetstormsecurity.com/files/153218/Exim-4.9.1-Remote-Command-Execution.htmlExploitThird Party AdvisoryVDB Entry
• packetstormsecurity.com/files/153312/Exim-4.91-Local-Privilege-Escalation.htmlExploitThird Party AdvisoryVDB Entry
• packetstormsecurity.com/files/154198/Exim-4.91-Local-Privilege-Escalation.htmlExploitThird Party AdvisoryVDB Entry
• seclists.org/fulldisclosure/2019/Jun/16Mailing ListThird Party Advisory
• www.openwall.com/lists/oss-security/2019/06/05/2Mailing ListThird Party Advisory
• www.openwall.com/lists/oss-security/2019/06/05/3Mailing ListPatchThird Party Advisory
• www.openwall.com/lists/oss-security/2019/06/05/4ExploitMailing List
• www.openwall.com/lists/oss-security/2019/06/06/1ExploitMailing ListThird Party Advisory
• www.openwall.com/lists/oss-security/2019/07/25/6Mailing ListThird Party Advisory
• www.openwall.com/lists/oss-security/2019/07/25/7Mailing ListThird Party Advisory
• www.openwall.com/lists/oss-security/2019/07/26/4Mailing ListThird Party Advisory
• www.openwall.com/lists/oss-security/2021/05/04/7Mailing ListThird Party Advisory
• www.securityfocus.com/bid/108679Broken LinkThird Party AdvisoryVDB Entry
• bugzilla.redhat.com/show_bug.cgiIssue TrackingThird Party Advisory
• seclists.org/bugtraq/2019/Jun/5Mailing ListThird Party Advisory
• security.gentoo.org/glsa/201906-01Third Party Advisory
• usn.ubuntu.com/4010-1Third Party Advisory
• www.debian.org/security/2019/dsa-4456Third Party Advisory
• www.exim.org/static/doc/security/CVE-2019-10149.txtVendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource