Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
Maven

GHSA-grg4-wf29-r9vv

HIGH

Bzip2Decoder doesn't allow setting size restrictions for decompressed data

Also known asCVE-2021-37136
Published
Sep 9, 2021
Updated
Mar 13, 2026
Affected
3 pkgs
Patched
1 / 3
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
5.7%probability of exploitation in next 30 days
Lower Risk92th percentile+4.46%
0.00%2.42%4.84%7.26%0.3%5.7%Dec 25Apr 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

3 pkgs affected
io.netty:netty-codecorg.jboss.netty:nettyio.netty:netty

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

The Bzip2 decompression decoder function doesn't allow setting size restrictions on the decompressed output data (which affects the allocation size used during decompression).

All users of Bzip2Decoder are affected. The malicious input can trigger an OOME and so a DoS attack

Workarounds

No workarounds other than not using the Bzip2Decoder

References

Relevant code areas:

https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/main/java/io/netty/handler/codec/compression/Bzip2Decoder.java#L80 https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/main/java/io/netty/handler/codec/compression/Bzip2Decoder.java#L294 https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/main/java/io/netty/handler/codec/compression/Bzip2Decoder.java#L305

Affected Packages

3 total 1 fixed
EcosystemPackageVulnerable rangeFix
Mavenio.netty:netty-codecall versions4.1.68.Final
Mavenorg.jboss.netty:nettyall versionsNo fix
Mavenio.netty:nettyall versionsNo fix

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-codec. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update io.netty:netty-codec to 4.1.68.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-grg4-wf29-r9vv is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-grg4-wf29-r9vv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-grg4-wf29-r9vv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact The Bzip2 decompression decoder function doesn't allow setting size restrictions on the decompressed output data (which affects the allocation size used during decompression). All users of Bzip2Decoder are affected. The malicious input can trigger an OOME and so a DoS attack ### Workarounds No workarounds other than not using the `Bzip2Decoder` ### References Relevant code areas: https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/main/java/io/netty/handler/codec/compression/Bzip2Decoder.java#L80 https://github.com/netty/netty/blob/netty-4.1.67.Final/codec/src/mai
O3 Security · Impact-Aware SCA

Is GHSA-grg4-wf29-r9vv in your dependencies?

O3 detects GHSA-grg4-wf29-r9vv across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-grg4-wf29-r9vv: netty-codec Denial of Service (High 7.5) | O3 Security