CVE-2023-34462 — Netty is an asynchronous event-driven network application framework for rapid de

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 d

01What is this vulnerability?

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…

02Affected products

Vendor	Product	Versions
netty	netty	< 4.1.94.Final

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-06-22T23:00:12.104Z
• Last modified: 2025-02-13T16:55:36.190Z

09References

• github.com — https://github.com/netty/netty/security/advisories/GHSA-6mjq-h674-j845
• github.com — https://github.com/netty/netty/commit/535da17e45201ae4278c0479e6162bb4127d4c32
• security.netapp.com — https://security.netapp.com/advisory/ntap-20230803-0001/
• www.debian.org — https://www.debian.org/security/2023/dsa-5558
• security.netapp.com — https://security.netapp.com/advisory/ntap-20240621-0007/