CVE-2021-4239
Weak encryption and denial of service in github.com/flynn/noise
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.
How to fix CVE-2021-4239
To remediate CVE-2021-4239, upgrade the affected package to a fixed version below.
- —upgrade to 1.0.0 or later
- —upgrade to 1.0.0 or later
- —upgrade to 1.0.0 or later
Is CVE-2021-4239 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 1.0.0
- from 0, < 1.0.0
- from 0, < 1.0.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H |