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.
Advisories
Source ID Title
EUVD EUVD EUVD-2023-35463 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.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00087}

epss

{'score': 0.00089}


Thu, 16 Jan 2025 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-02-13T16:49:46.904Z

Reserved: 2023-04-24T21:44:10.418Z

Link: CVE-2023-31147

cve-icon Vulnrichment

Updated: 2024-08-02T14:45:25.630Z

cve-icon NVD

Status : Modified

Published: 2023-05-25T22:15:09.833

Modified: 2024-11-21T08:01:29.420

Link: CVE-2023-31147

cve-icon Redhat

Severity : Moderate

Publid Date: 2023-05-22T00:00:00Z

Links: CVE-2023-31147 - Bugzilla

cve-icon OpenCVE Enrichment

No data.