Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2021-4239

7.5 · HIGH

The Noise protocol implementation suffers from weakened cryptographic security after encrypting 2^64 messages, and a potential denial of service attack.

Published Dec 27, 2022CWE-311EPSS 0.36%

Overview

CVE-2021-4239 is a high-severity vulnerability. It was published on December 27, 2022 and has a CVSS 3.1 base score of 7.5 (HIGH).

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical description

The Noise protocol implementation suffers from weakened cryptographic security after encrypting 2^64 messages, and a potential denial of service attack. After 2^64 (~18.4 quintillion) messages are encrypted with the Encrypt function, the nonce counter will wrap around, causing multiple messages to be encrypted with the same key and nonce. In a separate issue, the Decrypt function increments the nonce state even when it fails to decrypt a message. If an attacker can provide an invalid input to the Decrypt function, this will cause the nonce state to desynchronize between the peers, resulting in a failure to encrypt all subsequent messages.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

GitHubgithub.com/flynn/noise/pull/44Refpkg.go.dev/vuln/GO-2022-0425GitHubgithub.com/flynn/noise/pull/44Refpkg.go.dev/vuln/GO-2022-0425

How CyberStrike helps

Frequently asked questions

What is CVE-2021-4239?

CVE-2021-4239 is a high-severity vulnerability. It was published on December 27, 2022 and has a CVSS 3.1 base score of 7.5 (HIGH).

How severe is CVE-2021-4239?

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2021-4239?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2021-4239?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2021-4239 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related HIGH CVEs from 2021

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999