CVE-2020-12063

Publication date 24 April 2020

Last updated 24 July 2024


Ubuntu priority

Cvss 3 Severity Score

5.3 · Medium

Score breakdown

** 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.

Read the notes from the security team

Status

Package Ubuntu Release Status
postfix 20.04 LTS focal
Not affected
19.10 eoan
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected

Notes


mdeslaur

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

Severity score breakdown

Parameter Value
Base score 5.3 · Medium
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact Low
Availability impact None
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N