CVE-2025-58056
Netty is vulnerable to request smuggling due to incorrect parsing of chunk extensions
Description
Netty is an asynchronous event-driven network application framework for development of maintainable high performance protocol servers and clients. In versions 4.1.124.Final, and 4.2.0.Alpha3 through 4.2.4.Final, Netty incorrectly accepts standalone newline characters (LF) as a chunk-size line terminator, regardless of a preceding carriage return (CR), instead of requiring CRLF per HTTP/1.1 standards. When combined with reverse proxies that parse LF differently (treating it as part of the chunk extension), attackers can craft requests that the proxy sees as one request but Netty processes as two, enabling request smuggling attacks. This is fixed in versions 4.1.125.Final and 4.2.5.Final.
INFO
Published Date :
Sept. 3, 2025, 9:15 p.m.
Last Modified :
Sept. 8, 2025, 4:46 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Update Netty to version 4.1.125.Final or later.
- Update Netty to version 4.2.5.Final or later.
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-2025-58056.
| URL | Resource |
|---|---|
| https://datatracker.ietf.org/doc/html/rfc9112#name-chunked-transfer-coding | Technical Description |
| https://github.com/JLLeitschuh/unCVEed/issues/1 | Third Party Advisory Issue Tracking |
| https://github.com/netty/netty/commit/edb55fd8e0a3bcbd85881e423464f585183d1284 | Patch |
| https://github.com/netty/netty/issues/15522 | Issue Tracking |
| https://github.com/netty/netty/pull/15611 | Issue Tracking Patch |
| https://github.com/netty/netty/security/advisories/GHSA-fghv-69vj-qj49 | Exploit Vendor Advisory |
| https://w4ke.info/2025/06/18/funky-chunks.html | Broken Link |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-58056 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-2025-58056
weaknesses.
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).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-58056 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-58056 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.
-
Initial Analysis by [email protected]
Sep. 08, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.125 *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (excluding) 4.2.5 Added Reference Type GitHub, Inc.: https://datatracker.ietf.org/doc/html/rfc9112#name-chunked-transfer-coding Types: Technical Description Added Reference Type GitHub, Inc.: https://github.com/JLLeitschuh/unCVEed/issues/1 Types: Issue Tracking, Third Party Advisory Added Reference Type GitHub, Inc.: https://github.com/netty/netty/commit/edb55fd8e0a3bcbd85881e423464f585183d1284 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/netty/netty/issues/15522 Types: Issue Tracking Added Reference Type GitHub, Inc.: https://github.com/netty/netty/pull/15611 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/netty/netty/security/advisories/GHSA-fghv-69vj-qj49 Types: Exploit, Vendor Advisory Added Reference Type GitHub, Inc.: https://w4ke.info/2025/06/18/funky-chunks.html Types: Broken Link -
CVE Modified by [email protected]
Sep. 05, 2025
Action Type Old Value New Value Added CVSS V4.0 AV:N/AC:L/AT:P/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 Removed CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/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 -
New CVE Received by [email protected]
Sep. 03, 2025
Action Type Old Value New Value Added Description Netty is an asynchronous event-driven network application framework for development of maintainable high performance protocol servers and clients. In versions 4.1.124.Final, and 4.2.0.Alpha3 through 4.2.4.Final, Netty incorrectly accepts standalone newline characters (LF) as a chunk-size line terminator, regardless of a preceding carriage return (CR), instead of requiring CRLF per HTTP/1.1 standards. When combined with reverse proxies that parse LF differently (treating it as part of the chunk extension), attackers can craft requests that the proxy sees as one request but Netty processes as two, enabling request smuggling attacks. This is fixed in versions 4.1.125.Final and 4.2.5.Final. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/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 Added CWE CWE-444 Added Reference https://datatracker.ietf.org/doc/html/rfc9112#name-chunked-transfer-coding Added Reference https://github.com/JLLeitschuh/unCVEed/issues/1 Added Reference https://github.com/netty/netty/commit/edb55fd8e0a3bcbd85881e423464f585183d1284 Added Reference https://github.com/netty/netty/issues/15522 Added Reference https://github.com/netty/netty/pull/15611 Added Reference https://github.com/netty/netty/security/advisories/GHSA-fghv-69vj-qj49 Added Reference https://w4ke.info/2025/06/18/funky-chunks.html