CVE-2023-31147

Insufficient randomness in generation of DNS query IDs in c-ares

State
Published
Severity
5.9 Medium
Published
May 25, 2023
Updated
Feb 13, 2025
Reserved
Apr 24, 2023

Read the record on cve.org

Description

c-ares is an asynchronous resolver library. When /dev/urandom or RtlGenRandom() are unavailable, c-ares uses rand() to generate random numbers used for DNS query ids. This is not a CSPRNG, and it is also not seeded by srand() so will generate predictable output. Input from the random number generator is fed into a non-compilant RC4 implementation and may not be as strong as the original RC4 implementation. No attempt is made to look for modern OS-provided CSPRNGs like arc4random() that is widely available. This issue has been fixed in version 1.19.1.

Scores

CVSSScoreVectorSource
3.15.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:NGitHub_M

Weaknesses

  • CWE-330 Use of Insufficiently Random Values

Affected Products

ProductVersions
c-aresc-ares
  • < 1.19.1Affected

References

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