Authentication Bypass by Spoofing in OpenDMARC - CVE-2019-20790
Published: April 30, 2021
Vulnerability identifier: #VU52767
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-20790
CWE-ID: CWE-290
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass authentication process.
The vulnerability exists in OpenDMARC when used with pypolicyd-spf 2.0.2 when processing headers added by previous SPF filters. A remote attacker can bypass SPF and DMARC authentication in situations where the HELO field is inconsistent with the MAIL FROM field.
Affected software
OpenDMARC
Arch Linux
Fedora
opendmarc
Arch Linux
Fedora
opendmarc
How to mitigate CVE-2019-20790
Install updates from vendor's website.
OpenDMARC - update to 1.4.1
opendmarc - addressed in versions 1.4.1-1.el7, 1.4.1-1.el8, 1.4.1-1.fc33, 1.4.1-1.fc34
opendmarc - addressed in versions 1.4.1-1.el7, 1.4.1-1.el8, 1.4.1-1.fc33, 1.4.1-1.fc34
External References
- https://bugs.launchpad.net/pypolicyd-spf/+bug/1838816
- https://sourceforge.net/p/opendmarc/tickets/235/
- https://www.usenix.org/system/files/sec20fall_chen-jianjun_prepub_0.pdf
- https://github.com/trusteddomainproject/OpenDMARC/releases/tag/rel-opendmarc-1-4-1
- https://github.com/trusteddomainproject/OpenDMARC/blob/master/SECURITY/CVE-2019-20790