SB2019092108 - Signature validation bypass in OpenDMARC

Description

This security bulletin contains information about 1 security vulnerability.

1) Input validation error (CVE-ID: CVE-2019-16378)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in OpenDMARC implementation when processing emails with multiple "From:" addresses in a DKIM signed multi-from message. A remote attacker can create a specially crafted email message and bypass signature validation.

Successful exploitation of this vulnerability may allow an attacker to bypass implemented anti-spam measures.

Remediation

Install update from vendor's website.

References

• http://www.openwall.com/lists/oss-security/2019/09/17/2
• https://github.com/trusteddomainproject/OpenDMARC/pull/48
• https://seclists.org/bugtraq/2019/Sep/36
• https://www.openwall.com/lists/oss-security/2019/09/11/8
• https://github.com/trusteddomainproject/OpenDMARC/blob/master/SECURITY/CVE-2019-16378