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Fencer Intel
high 7.1

CVE-2023-51747 json

SMTP smuggling in Apache James

published 2y ago modified 4mo ago also EUVD-2024-0681 , GHSA-p5q9-86w4-2xr5

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 64%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.apache.james:james-server 3.7.5, 3.8.1
  • apache james 3.7.5, 3.8.1
  • org.apache.james james-server 3.7.5, 3.8.1

Is CVE-2023-51747 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-51747 updated cvss 7.4

apache-james: SMTP smuggling

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2y ago

Exploit prediction

1.05% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-15).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
GitHub 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

Affected packages

ecosystem package affected fixed in
maven org.apache.james:james-server
<3.7.5
>=3.8.0, <3.8.1
3.7.5
3.8.1

Affected products

  • Apache Software Foundation Apache James server

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-444 Inconsistent Interpretation of HTTP Requests
  • CWE-290 Authentication Bypass by Spoofing

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.