CVE-2021-37137 SnappyFrameDecoder doesn't restrict chunk length any may buffer skippable chunks in an unnecessary way
Attackers can cause excessive memory usage and denial of service in Netty applications by sending malicious compressed data or large skippable chunks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-37137?
CVE-2021-37137 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 19 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The Snappy frame decoder function doesn't restrict the chunk length which may lead to excessive memory usage. Beside this it also may buffer reserved skippable chunks until the whole chunk was received which may lead to excessive memory usage as well. This vulnerability can be triggered by supplying malicious input that decompresses to a very big size (via a network stream or a file) or by sending a huge skippable chunk.
Weakness: CWE-400
Which versions are affected by CVE-2021-37137?
6 open source packages ship an affected version, including io.netty:netty, io.netty:netty-codec and org.jboss.netty:netty. It affects 12 products.
| Package | Affected | Fixed in |
|---|---|---|
io.netty:netty Maven | All versions | None |
io.netty:netty Maven | All versions | None |
io.netty:netty-codec Maven | From 4.0.0 | 4.1.68.Final |
io.netty:netty-codec Maven | From 4.0.0 | 4.1.68.Final |
org.jboss.netty:netty Maven | All versions | None |
org.jboss.netty:netty Maven | All versions | None |
Products include Debian Debian Linux, Netapp Oncommand Insight, Netty Netty, Oracle Banking Apis, Oracle Banking Digital Experience, Oracle Commerce Guided Search and 6 more.
How do I fix CVE-2021-37137?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-37137 being exploited?
There is no known exploitation of CVE-2021-37137 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as CLEANSTART-2026-FK73993, DEBIAN-CVE-2021-37137, GHSA-9vjp-v76f-g363, MINI-m5mh-mmvq-grg4, MINI-rm58-h3jr-4vvc, UBUNTU-CVE-2021-37137.