Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The `SniHandler` can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the `SniHandler` to allocate 16MB of heap. The `SniHandler` class is a handler that waits for the TLS handshake to configure a `SslHandler` according to the indicated server name by the `ClientHello` record. For this matter it allocates a `ByteBuf` using the value defined in the `ClientHello` record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the `SslClientHelloHandler`. This vulnerability has been fixed in version 4.1.94.Final.
Advisories
Source ID Title
Debian DSA Debian DSA DSA-5558-1 netty security update
EUVD EUVD EUVD-2023-1713 Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The `SniHandler` can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the `SniHandler` to allocate 16MB of heap. The `SniHandler` class is a handler that waits for the TLS handshake to configure a `SslHandler` according to the indicated server name by the `ClientHello` record. For this matter it allocates a `ByteBuf` using the value defined in the `ClientHello` record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the `SslClientHelloHandler`. This vulnerability has been fixed in version 4.1.94.Final.
Github GHSA Github GHSA GHSA-6mjq-h674-j845 netty-handler SniHandler 16MB allocation
Ubuntu USN Ubuntu USN USN-6994-1 Netty vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00519}

epss

{'score': 0.00563}


Fri, 11 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00563}

epss

{'score': 0.00519}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-02-13T16:55:36.190Z

Reserved: 2023-06-06T16:16:53.560Z

Link: CVE-2023-34462

cve-icon Vulnrichment

Updated: 2024-08-02T16:10:07.000Z

cve-icon NVD

Status : Modified

Published: 2023-06-22T23:15:09.573

Modified: 2024-11-21T08:07:18.337

Link: CVE-2023-34462

cve-icon Redhat

Severity : Moderate

Publid Date: 2023-06-23T00:00:00Z

Links: CVE-2023-34462 - Bugzilla

cve-icon OpenCVE Enrichment

No data.