CVE-2019-20790

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-04-27 · updated 2026-06-17
Weakness: CWE-290

Description

OpenDMARC through 1.3.2 and 1.4.x, when used with pypolicyd-spf 2.0.2, allows attacks that bypass SPF and DMARC authentication in situations where the HELO field is inconsistent with the MAIL FROM field.

Affected products

Fedoraproject Fedora: 33, 34
Pypolicyd-Spf Project Pypolicyd-Spf: 2.0.2
Trusteddomain Opendmarc: from 1.3.0 through 1.3.2; 1.4.0

References

https://bugs.launchpad.net/pypolicyd-spf/+bug/1838816
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2D4JGHMALEJEWWG56DKR5OZB22TK7W5B/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KBOGOQOK3TIWWJV66MW5YWNRJAFFYGR5/
https://sourceforge.net/p/opendmarc/tickets/235/
https://www.usenix.org/system/files/sec20fall_chen-jianjun_prepub_0.pdf
https://bugs.launchpad.net/pypolicyd-spf/+bug/1838816
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2D4JGHMALEJEWWG56DKR5OZB22TK7W5B/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KBOGOQOK3TIWWJV66MW5YWNRJAFFYGR5/
https://sourceforge.net/p/opendmarc/tickets/235/
https://www.usenix.org/system/files/sec20fall_chen-jianjun_prepub_0.pdf

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