5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
7.3 High
AI Score
Confidence
Low
0.003 Low
EPSS
Percentile
65.3%
Issue Overview:
Postfix through 3.8.4 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Postfix supports <LF>.<CR><LF> but some other popular e-mail servers do not. To prevent attack variants (by always disallowing <LF> without <CR>), a different solution is required: the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23, 3.6.13, 3.7.9, 3.8.4, or 3.9. (CVE-2023-51764)
Affected Packages:
postfix
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update postfix to update your system.
New Packages:
aarch64:
postfix-2.10.1-6.amzn2.0.4.aarch64
postfix-perl-scripts-2.10.1-6.amzn2.0.4.aarch64
postfix-debuginfo-2.10.1-6.amzn2.0.4.aarch64
i686:
postfix-2.10.1-6.amzn2.0.4.i686
postfix-perl-scripts-2.10.1-6.amzn2.0.4.i686
postfix-debuginfo-2.10.1-6.amzn2.0.4.i686
noarch:
postfix-sysvinit-2.10.1-6.amzn2.0.4.noarch
src:
postfix-2.10.1-6.amzn2.0.4.src
x86_64:
postfix-2.10.1-6.amzn2.0.4.x86_64
postfix-perl-scripts-2.10.1-6.amzn2.0.4.x86_64
postfix-debuginfo-2.10.1-6.amzn2.0.4.x86_64
Red Hat: CVE-2023-51764
Mitre: CVE-2023-51764
5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
7.3 High
AI Score
Confidence
Low
0.003 Low
EPSS
Percentile
65.3%