Vulnerability in Postfix

CVE-2020-12063

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

EPSS: 0.009 (57.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

  • Postfix — versions 2.10.1
  • N/a — versions n/a

References

  • cve@mitre.org (Mailing List, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Exploit, Mailing List, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2020-12063?
CVE-2020-12063 is a medium-severity vulnerability in Postfix. CVSS score: 5.3/10. Published 2020-04-24.
How severe is CVE-2020-12063?
Medium severity. CVSS v3 base score is 5.3 out of 10.