{"cve":"CVE-2025-31498","nvd":{"published":"2025-04-08T14:15:35.293","modified":"2026-06-17T09:10:30.347","status":"Deferred","description":"c-ares is an asynchronous resolver library. From 1.32.3 through 1.34.4, there is a use-after-free in read_answers() when process_answer() may re-enqueue a query either due to a DNS Cookie Failure or when the upstream server does not properly support EDNS, or possibly on TCP queries if the remote closed the connection immediately after a response. If there was an issue trying to put that new transaction on the wire, it would close the connection handle, but read_answers() was still expecting the connection handle to be available to possibly dequeue other responses. In theory a remote attacker might be able to trigger this by flooding the target with ICMP UNREACHABLE packets if they also control the upstream nameserver and can return a result with one of those conditions, this has been untested. Otherwise only a local attacker might be able to change system behavior to make send()/write() return a failure condition. This vulnerability is fixed in 1.34.5.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N","score":8.3},"cvss_v3":null,"cwes":["CWE-416"],"references":["https://github.com/c-ares/c-ares/commit/29d38719112639d8c0ba910254a3dd4f482ea2d1","https://github.com/c-ares/c-ares/pull/821","https://github.com/c-ares/c-ares/security/advisories/GHSA-6hxc-62jh-p29v","http://www.openwall.com/lists/oss-security/2025/04/08/3"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:00:57.946988208+00:00"},"epss":{"cve":"CVE-2025-31498","score":0.0059,"percentile":0.48219,"date":"2026-10-31"},"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."]}