Postfix 2.10.1-7 sender_login Homoglyph data authenticity ⚔ [Disputed]

Summaryinfo

A vulnerability, which was classified as critical, has been found in Postfix 2.10.1-7. Affected is an unknown function of the file /etc/postfix/sender_login. This manipulation with the input \xce\xbf as part of Homoglyph causes data authenticity. This vulnerability is handled as CVE-2020-12063. The attack can be initiated remotely. There is not any exploit available. The actual existence of this vulnerability is currently in question.

Detailsinfo

A vulnerability classified as critical was found in Postfix 2.10.1-7. Affected by this vulnerability is an unknown functionality of the file /etc/postfix/sender_login. The manipulation with the input value \xce\xbf leads to a data authenticity vulnerability. The CWE definition for the vulnerability is CWE-345. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

** 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.

The weakness was released 04/24/2020. This vulnerability is known as CVE-2020-12063 since 04/22/2020. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/04/2024).

The real existence of this vulnerability is still doubted at the moment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• Postfix

Version

• 2.10.1-7

CPE 2.3info

• 🔍

CPE 2.2info

• 🔍

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