CVE-2025-59419

Aliases:GHSA-jq43-27x9-3v86
Advisory lineage Upstream: 0 Downstream: 7
Deferred
Published: 15 Oct 2025, 15:42
Last modified:17 Oct 2025, 19:44

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v4.0 (cve.org)
EPSS Score
0.24% LOW
0% probability -0.73%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

15 Oct 2025, 15:42
Published
Vulnerability first disclosed
17 Oct 2025, 19:44
Last Modified
Vulnerability information updated

Description

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.128.Final and 4.2.7.Final, the SMTP codec in Netty contains an SMTP command injection vulnerability due to insufficient input validation for Carriage Return (\r) and Line Feed (\n) characters in user-supplied parameters. The vulnerability exists in io.netty.handler.codec.smtp.DefaultSmtpRequest, where parameters are directly concatenated into the SMTP command string without sanitization. When methods such as SmtpRequests.rcpt(recipient) are called with a malicious string containing CRLF sequences, attackers can inject arbitrary SMTP commands. Because the injected commands are sent from the server's trusted IP address, resulting emails will likely pass SPF and DKIM authentication checks, making them appear legitimate. This allows remote attackers who can control SMTP command parameters (such as email recipients) to forge arbitrary emails from the trusted server, potentially impersonating executives and forging high-stakes corporate communications. This issue has been patched in versions 4.1.129.Final and 4.2.8.Final. No known workarounds exist.

CVSS Metrics

  • v4.0•MEDIUM•Score: 5.5CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
  • v4.0•MEDIUM•Score: 5.5CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
  • v4.0•HIGH•Score: 8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

EPSS Trends

Current EPSS score: 0.24%• Percentile: 47%

Techniques & Countermeasures

  • CWE-93•Improper Neutralization of CRLF Sequences ('CRLF Injection')

    The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.

Affected Systems

  • io.netty•netty-codec-smtp

    ≥ 4.2.0.Alpha1, < 4.2.7.Final | < 4.1.128.Final

  • netty•netty

    < 4.2.7.Final | ≥ 4.2.0.Alpha1, < 4.1.128.Final

References (7)