PT-2023-8127 · Postfix+8 · Postfix+8
Timo Longin
·
Publicado
2023-12-18
·
Atualizado
2025-03-17
·
CVE-2023-51764
CVSS v3.1
5.3
Média
| Vetor | AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
Name of the Vulnerable Software and Affected Versions
Postfix versions 3.5.23 through 3.8.5
Postfix versions prior to 3.9
Description
The issue is related to insufficient validation of line endings in the Postfix smtpd daemon, allowing remote attackers to bypass security restrictions and perform email spoofing attacks, such as SMTP Smuggling. This can be exploited by injecting email messages with a spoofed MAIL FROM address, bypassing SPF protection mechanisms. The vulnerability occurs because Postfix supports
<LF>.<CR><LF> while other popular email servers do not.Recommendations
For Postfix versions 3.5.23 through 3.8.4, consider configuring
smtpd data restrictions=reject unauth pipelining and smtpd discard ehlo keywords=chunking to prevent SMTP smuggling.
For Postfix versions 3.5.23, 3.6.13, 3.7.9, 3.8.4, or 3.9, consider setting smtpd forbid bare newline=yes to disallow <LF> without <CR>.
As a temporary workaround, consider restricting access to the vulnerable smtpd daemon until a patch is available.Exploit
Correção
UI Misrepresentation of Critical Information
Insufficient Verification of Data Authenticity
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Identificadores relacionados
Produtos afetados
Alt Linux
Almalinux
Linuxmint
Postfix
Red Hat
Red Os
Rocky Linux
Suse
Ubuntu