CVE-2020-12063

Public Exploit

Description

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

5.3

CVSS

Severity: Medium

CVSS 3.1 •

CVSS 2.0 •

EPSS 0.44%

Third-Party Advisory openwall.com Third-Party Advisory openwall.com

Affected: n/a n/a

References

Link	Tags
https://www.openwall.com/lists/oss-security/2020/04/23/3	third party advisory mailing list
https://www.openwall.com/lists/oss-security/2020/04/23/12	mailing list third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2020-12063?: CVE-2020-12063 has been scored as a medium severity vulnerability.
How to fix CVE-2020-12063?: To fix CVE-2020-12063, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-12063 being actively exploited in the wild?: It is possible that CVE-2020-12063 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.

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