CVE-2023-51747

Name: CVE-2023-51747
Creator: NVD / NIST
Published: 2024-02-27T14:15:27.03+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.1/10EPSS 1.04%

Last modified Jun 17, 2026

CVE-2023-51747 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling. A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks. The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction. We recommend James users to upgrade to non vulnerable versions.. EPSS estimates a 1.04% chance of exploitation in the next 30 days.

Description

Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling. A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks. The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction. We recommend James users to upgrade to non vulnerable versions.

Metrics

CVSS 3.1

7.1/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

EPSS Probability

1.04%

59.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apache	James	3.7.5
Apache	James	3.8.1

References

http://www.openwall.com/lists/oss-security/2024/02/27/4Mailing List, Third Party Advisory
https://lists.apache.org/thread/rxkwbkh9vgbl9rzx1fkllyk3krhgydkoMailing List, Vendor Advisory
https://postfix.org/smtp-smuggling.htmlProduct
https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/Product
http://www.openwall.com/lists/oss-security/2024/02/27/4Mailing List, Third Party Advisory
https://lists.apache.org/thread/rxkwbkh9vgbl9rzx1fkllyk3krhgydkoMailing List, Vendor Advisory
https://postfix.org/smtp-smuggling.htmlProduct
https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/Product

Timeline

Published: Feb 27, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2023-51747?

How severe is CVE-2023-51747?

CVE-2023-51747 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 1.04% probability of exploitation in the next 30 days.

How do I fix CVE-2023-51747?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-51747?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST