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SnappyFrameDecoder doesn't restrict chunk length any may buffer skippable chunks in an unnecessary way

Moderate
normanmaurer published GHSA-9vjp-v76f-g363 Sep 9, 2021

Package

maven netty-codec (Maven)

Affected versions

< 4.1.68.Final

Patched versions

4.1.68.Final

Description

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

For more information

If you have any questions or comments about this advisory:

Severity

Moderate

CVE ID

CVE-2021-37137

Weaknesses

No CWEs

Credits