# CVE-2021-21290: Local Information Disclosure Vulnerability in Netty on Unix-Like systems

Source: https://junglewise.ai/threats/cve-2021-21290-local-information-disclosure-vulnerability-in-netty-on-unix-like  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-02-08  
License: CC BY 4.0 with a link back

CVE-2021-21290 · Severity: low · CVSS 3.1 · Published 2021-02-08

Local Information Disclosure Vulnerability in Netty on Unix-Like systems

Technologies: [io.netty:netty (Maven)](https://junglewise.ai/threats/technologies/io-netty-netty), [io.netty:netty-codec-http (Maven)](https://junglewise.ai/threats/technologies/io-netty-netty-codec-http), [org.jboss.netty:netty (Maven)](https://junglewise.ai/threats/technologies/org-jboss-netty-netty). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2021-21290 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-21290 being exploited in the wild.

**How severe is CVE-2021-21290?** Low severity, with a CVSS score of 3.1, published 8 February 2021.

**Which products and versions are affected?** io.netty:netty (Maven) ECOSYSTEM:introduced=0; io.netty:netty-codec-http (Maven) ECOSYSTEM:introduced=4.0.0,fixed=4.1.59.Final; org.jboss.netty:netty (Maven) ECOSYSTEM:introduced=0.

**Is there a fix for CVE-2021-21290?** Yes. io.netty:netty-codec-http (Maven): upgrade to 4.1.59.Final or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-21290?** Check whether you run io.netty:netty (Maven), io.netty:netty-codec-http (Maven) or org.jboss.netty:netty (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- io.netty:netty-codec-http (Maven): upgrade to 4.1.59.Final or later

  ```sh
  # set io.netty:netty-codec-http to 4.1.59.Final in your pom.xml or build.gradle
  ```


## Affected products

- io.netty:netty (Maven) ECOSYSTEM:introduced=0
- io.netty:netty-codec-http (Maven) ECOSYSTEM:introduced=4.0.0,fixed=4.1.59.Final
- org.jboss.netty:netty (Maven) ECOSYSTEM:introduced=0

## Identifiers

- CVE-2021-21290
- GHSA-5mcr-gq6c-3hq2

## Related threats

- [Netty CorsHandler cache poisoning via Vary header overwrite](https://junglewise.ai/threats/cve-2026-59903-netty-corshandler-cache-poisoning-via-vary-header-overwrite)
- [Netty HTTP request smuggling via lax WebSocket handshake validation](https://junglewise.ai/threats/cve-2026-59898-netty-http-request-smuggling-via-lax-websocket-handshake)
- [Netty resource exhaustion in HttpContentEncoder via HTTP pipelining](https://junglewise.ai/threats/cve-2026-59899-netty-resource-exhaustion-in-httpcontentencoder-via-http)
- [Netty CRLF injection in HttpPostRequestEncoder multipart filenames](https://junglewise.ai/threats/cve-2026-59921-netty-crlf-injection-in-httppostrequestencoder-multipart)
- [Netty security bypass in CorsHandler origin evaluation](https://junglewise.ai/threats/cve-2026-56746-netty-security-bypass-in-corshandler-origin-evaluation)