5.3
MEDIUM
CVE-2023-51765
Sendmail SMTP Smuggling Vulnerability
Description

sendmail through 8.17.2 allows SMTP smuggling in certain configurations. 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 sendmail supports <LF>.<CR><LF> but some other popular e-mail servers do not. This is resolved in 8.18 and later versions with 'o' in srv_features.

INFO

Published Date :

Dec. 24, 2023, 6:15 a.m.

Last Modified :

June 15, 2024, 9:15 a.m.

Source :

[email protected]

Remotely Exploitable :

Yes !

Impact Score :

1.4

Exploitability Score :

3.9
Public PoC/Exploit Available at Github

CVE-2023-51765 has a 3 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2023-51765 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Redhat enterprise_linux
1 Freebsd freebsd
1 Sendmail sendmail
: Total Affected Vendor : 3 | Products : 3
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2023-51765.

URL Resource
http://www.openwall.com/lists/oss-security/2023/12/24/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/25/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/26/5 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/29/5 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/30/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/30/3 Mailing List Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-51765 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2255869 Issue Tracking Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1218351 Issue Tracking Patch Third Party Advisory
https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html Technical Description
https://github.com/freebsd/freebsd-src/commit/5dd76dd0cc19450133aa379ce0ce4a68ae07fb39#diff-afdf514b32ac88004952c11660c57bc96c3d8b2234007c1cbd8d7ed7fd7935cc Patch
https://lists.debian.org/debian-lts-announce/2024/06/msg00004.html
https://lwn.net/Articles/956533/
https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/ Technical Description Third Party Advisory
https://www.openwall.com/lists/oss-security/2023/12/21/7 Mailing List Third Party Advisory
https://www.openwall.com/lists/oss-security/2023/12/22/7 Mailing List Third Party Advisory
https://www.youtube.com/watch?v=V8KPV96g1To Exploit

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Profile Photo
eeenvik1/CVE-2023-51764

PoC CVE-2023-51764

cve

Python

Updated: 8 months ago
3 stars 3 fork 3 watcher
Born at : Dec. 28, 2023, 6:20 a.m. This repo has been linked 2 different CVEs too.
Profile Photo
hannob/smtpsmug

None

Python Shell

Updated: 2 months, 2 weeks ago
94 stars 13 fork 13 watcher
Born at : Dec. 21, 2023, 8:13 p.m. This repo has been linked 3 different CVEs too.
Profile Photo
sagredo-dev/qmail

qmail is a secure, reliable, efficient, simple message transfer agent.

qmail dkim smtp spf srs tls mailserver

Makefile Roff C Shell GAP C++ HTML

Updated: 4 weeks ago
5 stars 6 fork 6 watcher
Born at : Dec. 3, 2023, 10:31 a.m. This repo has been linked 2 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2023-51765 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2023-51765 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Jun. 15, 2024

    Action Type Old Value New Value
    Added Reference MITRE https://lists.debian.org/debian-lts-announce/2024/06/msg00004.html [No types assigned]
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Jan. 18, 2024

    Action Type Old Value New Value
    Added Reference MITRE https://lwn.net/Articles/956533/ [No types assigned]
  • CVE Modified by [email protected]

    Jan. 09, 2024

    Action Type Old Value New Value
    Changed Description sendmail through at least 8.14.7 allows SMTP smuggling in certain configurations. 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 sendmail supports <LF>.<CR><LF> but some other popular e-mail servers do not. sendmail through 8.17.2 allows SMTP smuggling in certain configurations. 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 sendmail supports <LF>.<CR><LF> but some other popular e-mail servers do not. This is resolved in 8.18 and later versions with 'o' in srv_features.
  • Initial Analysis by [email protected]

    Jan. 05, 2024

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
    Changed Reference Type http://www.openwall.com/lists/oss-security/2023/12/24/1 No Types Assigned http://www.openwall.com/lists/oss-security/2023/12/24/1 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2023/12/25/1 No Types Assigned http://www.openwall.com/lists/oss-security/2023/12/25/1 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2023/12/26/5 No Types Assigned http://www.openwall.com/lists/oss-security/2023/12/26/5 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2023/12/29/5 No Types Assigned http://www.openwall.com/lists/oss-security/2023/12/29/5 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2023/12/30/1 No Types Assigned http://www.openwall.com/lists/oss-security/2023/12/30/1 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2023/12/30/3 No Types Assigned http://www.openwall.com/lists/oss-security/2023/12/30/3 Mailing List, Third Party Advisory
    Changed Reference Type https://access.redhat.com/security/cve/CVE-2023-51765 No Types Assigned https://access.redhat.com/security/cve/CVE-2023-51765 Third Party Advisory
    Changed Reference Type https://bugzilla.redhat.com/show_bug.cgi?id=2255869 No Types Assigned https://bugzilla.redhat.com/show_bug.cgi?id=2255869 Issue Tracking, Third Party Advisory
    Changed Reference Type https://bugzilla.suse.com/show_bug.cgi?id=1218351 No Types Assigned https://bugzilla.suse.com/show_bug.cgi?id=1218351 Issue Tracking, Patch, Third Party Advisory
    Changed Reference Type https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html No Types Assigned https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html Technical Description
    Changed Reference Type https://github.com/freebsd/freebsd-src/commit/5dd76dd0cc19450133aa379ce0ce4a68ae07fb39#diff-afdf514b32ac88004952c11660c57bc96c3d8b2234007c1cbd8d7ed7fd7935cc No Types Assigned https://github.com/freebsd/freebsd-src/commit/5dd76dd0cc19450133aa379ce0ce4a68ae07fb39#diff-afdf514b32ac88004952c11660c57bc96c3d8b2234007c1cbd8d7ed7fd7935cc Patch
    Changed Reference Type https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/ No Types Assigned https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/ Technical Description, Third Party Advisory
    Changed Reference Type https://www.openwall.com/lists/oss-security/2023/12/21/7 No Types Assigned https://www.openwall.com/lists/oss-security/2023/12/21/7 Mailing List, Third Party Advisory
    Changed Reference Type https://www.openwall.com/lists/oss-security/2023/12/22/7 No Types Assigned https://www.openwall.com/lists/oss-security/2023/12/22/7 Mailing List, Third Party Advisory
    Changed Reference Type https://www.youtube.com/watch?v=V8KPV96g1To No Types Assigned https://www.youtube.com/watch?v=V8KPV96g1To Exploit
    Added CWE NIST CWE-345
    Added CPE Configuration OR *cpe:2.3:a:sendmail:sendmail:*:*:*:*:*:*:*:* versions up to (excluding) 8.18.0.2
    Added CPE Configuration OR *cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:* versions up to (excluding) 11.0
    Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Jan. 04, 2024

    Action Type Old Value New Value
    Added Reference MITRE https://www.youtube.com/watch?v=V8KPV96g1To [No types assigned]
  • CVE Modified by [email protected]

    Dec. 30, 2023

    Action Type Old Value New Value
    Added Reference MITRE http://www.openwall.com/lists/oss-security/2023/12/30/3 [No types assigned]
    Added Reference MITRE http://www.openwall.com/lists/oss-security/2023/12/30/1 [No types assigned]
  • CVE Modified by [email protected]

    Dec. 30, 2023

    Action Type Old Value New Value
    Added Reference MITRE http://www.openwall.com/lists/oss-security/2023/12/29/5 [No types assigned]
  • CVE Modified by [email protected]

    Dec. 26, 2023

    Action Type Old Value New Value
    Added Reference MITRE https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html [No types assigned]
    Added Reference MITRE http://www.openwall.com/lists/oss-security/2023/12/26/5 [No types assigned]
  • CVE Modified by [email protected]

    Dec. 26, 2023

    Action Type Old Value New Value
    Changed Description sendmail through at least 8.14.7 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 sendmail server, allowing bypass of an SPF protection mechanism. This occurs because sendmail supports <LF>.<CR><LF> but some other popular e-mail servers do not. sendmail through at least 8.14.7 allows SMTP smuggling in certain configurations. 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 sendmail supports <LF>.<CR><LF> but some other popular e-mail servers do not.
    Added Reference MITRE http://www.openwall.com/lists/oss-security/2023/12/25/1 [No types assigned]
    Added Reference MITRE https://bugzilla.suse.com/show_bug.cgi?id=1218351 [No types assigned]
    Added Reference MITRE https://bugzilla.redhat.com/show_bug.cgi?id=2255869 [No types assigned]
    Added Reference MITRE https://access.redhat.com/security/cve/CVE-2023-51765 [No types assigned]
  • CVE Modified by [email protected]

    Dec. 24, 2023

    Action Type Old Value New Value
    Added Reference MITRE http://www.openwall.com/lists/oss-security/2023/12/24/1 [No types assigned]
  • CVE Received by [email protected]

    Dec. 24, 2023

    Action Type Old Value New Value
    Added Description sendmail through at least 8.14.7 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 sendmail server, allowing bypass of an SPF protection mechanism. This occurs because sendmail supports <LF>.<CR><LF> but some other popular e-mail servers do not.
    Added Reference MITRE https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/ [No types assigned]
    Added Reference MITRE https://www.openwall.com/lists/oss-security/2023/12/22/7 [No types assigned]
    Added Reference MITRE https://www.openwall.com/lists/oss-security/2023/12/21/7 [No types assigned]
    Added Reference MITRE https://github.com/freebsd/freebsd-src/commit/5dd76dd0cc19450133aa379ce0ce4a68ae07fb39#diff-afdf514b32ac88004952c11660c57bc96c3d8b2234007c1cbd8d7ed7fd7935cc [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2023-51765 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2023-51765 weaknesses.

CAPEC-111: JSON Hijacking (aka JavaScript Hijacking) JSON Hijacking (aka JavaScript Hijacking) CAPEC-141: Cache Poisoning Cache Poisoning CAPEC-142: DNS Cache Poisoning DNS Cache Poisoning CAPEC-148: Content Spoofing Content Spoofing CAPEC-218: Spoofing of UDDI/ebXML Messages Spoofing of UDDI/ebXML Messages CAPEC-384: Application API Message Manipulation via Man-in-the-Middle Application API Message Manipulation via Man-in-the-Middle CAPEC-385: Transaction or Event Tampering via Application API Manipulation Transaction or Event Tampering via Application API Manipulation CAPEC-386: Application API Navigation Remapping Application API Navigation Remapping CAPEC-387: Navigation Remapping To Propagate Malicious Content Navigation Remapping To Propagate Malicious Content CAPEC-388: Application API Button Hijacking Application API Button Hijacking CAPEC-665: Exploitation of Thunderbolt Protection Flaws Exploitation of Thunderbolt Protection Flaws CAPEC-701: Browser in the Middle (BiTM) Browser in the Middle (BiTM)
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.17 }} 0.06%

score

0.54460

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: