CVE-2023-1732
Leaked shared secret and weak blinding in github.com/cloudflare/circl
Description
When sampling randomness for a shared secret, the implementation of Kyber and FrodoKEM, did not check whether crypto/rand.Read() returns an error. In rare deployment cases (error thrown by the Read() function), this could lead to a predictable shared secret. The tkn20 and blindrsa components did not check whether enough randomness was returned from the user provided randomness source. Typically the user provides crypto/rand.Reader, which in the vast majority of cases will always return the right number random bytes. In the cases where it does not, or the user provides a source that does not, the blinding for blindrsa is weak and integrity of the plaintext is not ensured in tkn20.
How to fix CVE-2023-1732
To remediate CVE-2023-1732, upgrade the affected package to a fixed version below.
- —upgrade to 1.3.3 or later
- —upgrade to 1.3.3 or later
Is CVE-2023-1732 being exploited?
Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 1.3.3
- from 0, < 1.3.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N |