{"id":"CVE-2021-4239","details":"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.","aliases":["GHSA-6cr6-fmvc-vw2p","GHSA-g9mp-8g3h-3c5c","GO-2022-0425"],"modified":"2026-03-14T14:58:40.244533Z","published":"2022-12-27T22:15:12.123Z","references":[{"type":"FIX","url":"https://github.com/flynn/noise/pull/44"},{"type":"FIX","url":"https://pkg.go.dev/vuln/GO-2022-0425"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-4239.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}