CVE-2020-12063

Published: 24 April 2020

** DISPUTED ** A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender via a homoglyph attack, as demonstrated by the similarity of \xce\xbf to the 'o' character. This is potentially relevant when the /etc/postfix/sender_login feature is used, because a spoofed outbound message that uses a configured sender address is blocked with a "Sender address rejected: not logged in" error message, but a spoofed outbound message that uses a homoglyph of a configured sender address is not blocked. NOTE: some third parties argue that any missed blocking of spoofed outbound messages - except for exact matches to a sender address in the /etc/postfix/sender_login file - is outside the design goals of Postfix and thus cannot be considered a Postfix vulnerability.

Notes

upstream Postfix project has disputed this vulnerability,
marking as not-affected.

Status

Severity score breakdown

References

• https://www.openwall.com/lists/oss-security/2020/04/23/3
• https://www.openwall.com/lists/oss-security/2020/04/23/12
• https://www.cve.org/CVERecord?id=CVE-2020-12063
• NVD
• Launchpad
• Debian