Bug 2255852 (CVE-2023-51766) - CVE-2023-51766 exim: SMTP smuggling vulnerability
Summary: CVE-2023-51766 exim: SMTP smuggling vulnerability
Keywords:
Status: NEW
Alias: CVE-2023-51766
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2255853 2255854
Blocks: 2255562
TreeView+ depends on / blocked
 
Reported: 2023-12-25 20:01 UTC by Robb Gatica
Modified: 2024-01-24 08:41 UTC (History)
0 users

Fixed In Version:
Doc Type: ---
Doc Text:
A flaw was discovered in exim that allows a remote attacker to exploit a weakness in some SMTP server configurations. This makes it possible to break out of the email message data to "smuggle" SMTP commands and send spoofed emails which pass SPF checks.
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)

Description Robb Gatica 2023-12-25 20:01:38 UTC 
Source: exim4
Version: 4.97-2
Severity: important
Tags: security upstream
Forwarded: https://bugs.exim.org/show_bug.cgi?id=3063
X-Debbugs-Cc: carnil, Debian Security Team <team.org>

Hi,

The following vulnerability was published for exim4.

CVE-2023-51766[0]:
| Exim through 4.97 allows SMTP smuggling in certain configurations.
| Remote attackers can use a published exploitation technique to
| inject e-mail messages that appear to originate from the Exim
| server, allowing bypass of an SPF protection mechanism. This occurs
| because Exim supports <LF>.<CR><LF> but some other popular e-mail
| servers do not.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2023-51766
    https://www.cve.org/CVERecord?id=CVE-2023-51766
[1] https://bugs.exim.org/show_bug.cgi?id=3063
Comment 1 Robb Gatica 2023-12-25 20:01:52 UTC 
Created exim tracking bugs for this issue:

Affects: epel-all [bug 2255854]
Affects: fedora-all [bug 2255853]
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