CVE-2021-37137: High severity Netty Netty vulnerability
Impact 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.
Impact
All users of SnappyFrameDecoder are affected and so the application may be in risk for a DoS attach due excessive memory usage.
References https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/main/java/io/netty/handler/codec/compression/SnappyFrameDecoder.java#L79 https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/main/java/io/netty/handler/codec/compression/SnappyFrameDecoder.java#L171 https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/main/java/io/netty/handler/codec/compression/SnappyFrameDecoder.java#L185
Other sources
A flaw was found in the Netty's netty-codec due to unrestricted chunk lengths in the SnappyFrameDecoder. By sending a specially-crafted input, a remote attacker could cause excessive memory usage resulting in a denial of service.
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.
Reference: https://github.com/netty/netty/security/advisories/GHSA-9vjp-v76f-g363
— Red Hat
Affected Software
Remediation
Patch Available
Patch Available
Patch Available
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2021-37137?
CVE-2021-37137 is a vulnerability in the Netty library that allows for unrestricted chunk lengths and can lead to excessive memory usage.
How does CVE-2021-37137 impact systems?
CVE-2021-37137 can result in excessive memory usage due to unrestricted chunk lengths in the Snappy frame decoder function.
What is the severity of CVE-2021-37137?
The severity of CVE-2021-37137 is high with a CVSS score of 7.
Which software versions are affected by CVE-2021-37137?
Netty versions up to 4.1.68 are affected, as well as specific versions of Red Hat EAP7-Netty, Ubuntu Netty, and Debian Netty.
How can I mitigate the vulnerability (CVE-2021-37137)?
To mitigate CVE-2021-37137, upgrade to Netty version 4.1.68 or later, and apply any relevant patches for the affected software versions.