CVE-2021-21409
moderate-risk
Published 2021-03-30
Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty (io.netty:netty-codec-http2) before version 4.1.61.Final there is a vulnerability that enables request smuggling. The content-length header is not correctly validated if the request only uses a single Http2HeaderFrame with the endStream set to to true. This could lead to request smuggling if the request is proxied to a remote peer and translated to HTTP/1.1. This is a followup of GHSA-wm47-8v5p-wjpj/CVE-2021-21295 which did miss to fix this one case. This was fixed as part of 4.1.61.Final.
Do I need to act?
~
2.5% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.9/10
Medium
NETWORK
/ HIGH complexity
Affected Products (20)
Oncommand Api Services
Communications Design Studio
References (118)
Third Party Advisory
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21295
Third Party Advisory
https://github.com/netty/netty/security/advisories/GHSA-f256-j965-7f32
Third Party Advisory
https://github.com/netty/netty/security/advisories/GHSA-wm47-8v5p-wjpj
and 98 more references
45
/ 100
moderate-risk
Severity
18/34 · Moderate
Exploitability
6/34 · Minimal
Exposure
21/34 · High