CVE-2019-20790

Name: CVE-2019-20790
Creator: NVD / NIST
Published: 2020-04-27T14:15:11.127+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.66%

Last modified Jun 17, 2026

CVE-2019-20790 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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.. EPSS estimates a 2.66% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.66%

83.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-290

Affected Software

Vendor	Product	Versions
Trusteddomain	Opendmarc	>= 1.3.0, <= 1.3.2
Trusteddomain	Opendmarc	1.4.0
Pypolicyd-Spf Project	Pypolicyd-Spf	2.0.2
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34

References

https://bugs.launchpad.net/pypolicyd-spf/+bug/1838816Exploit, Third Party Advisory
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/Exploit, Third Party Advisory
https://www.usenix.org/system/files/sec20fall_chen-jianjun_prepub_0.pdfTechnical Description, Third Party Advisory
https://bugs.launchpad.net/pypolicyd-spf/+bug/1838816Exploit, Third Party Advisory
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/Exploit, Third Party Advisory
https://www.usenix.org/system/files/sec20fall_chen-jianjun_prepub_0.pdfTechnical Description, Third Party Advisory

Timeline

Published: Apr 27, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-20790?

How severe is CVE-2019-20790?

CVE-2019-20790 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.66% probability of exploitation in the next 30 days.

How do I fix CVE-2019-20790?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-20790?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST