{"cve":"CVE-2023-31147","nvd":{"published":"2023-05-25T22:15:09.833","modified":"2026-06-17T05:56:22.987","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","score":6.5},"cwes":["CWE-330"],"references":["https://github.com/c-ares/c-ares/releases/tag/cares-1_19_1","https://github.com/c-ares/c-ares/security/advisories/GHSA-8r8p-23f3-64c2","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/B5Z5XFNXTNPTCBBVXFDNZQVLLIE6VRBY/","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UBFWILTA33LOSV23P44FGTQQIDRJHIY7/","https://security.gentoo.org/glsa/202310-09"],"products":["c-ares_project:c-ares","fedoraproject:fedora"],"source":"nvd","synced_at":"2026-10-19T21:38:24.161619714+00:00"},"epss":{"cve":"CVE-2023-31147","score":0.00897,"percentile":0.59606,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}