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Fencer Vulns
medium 5.3

CVE-2023-1732 json

Improper random reading in CIRCL

published 2023-05-10 3 y ago modified 2026-09-10 1 mo ago also GHSA-2q89-485c-9j2x , GO-2023-1765 , EUVD-2023-1452

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/cloudflare/circl 1.3.3
  • Cloudflare CIRCL <1.3.3
  • velociraptor openSUSE Tumbleweed 0.7.0.4.git142.862ef23-1.1

opensuse advisories openSUSE-SU-2025:14663-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-1732 updated cvss 5.3

CIRCL: Improper random reading in CIRCL

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
21 mo ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N
NVD 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/cloudflare/circl
<1.3.3
1.3.3

Affected products

  • Cloudflare CIRCL

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-755 Improper Handling of Exceptional Conditions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.