{"cve":"CVE-2021-3594","nvd":{"published":"2021-06-15T21:15:09.993","modified":"2026-06-17T04:05:24.177","status":"Modified","description":"An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the udp_input() function and could occur while processing a udp packet that is smaller than the size of the 'udphdr' structure. This issue may lead to out-of-bounds read access or indirect host memory disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N","score":3.8},"cwes":["CWE-824"],"references":["https://bugzilla.redhat.com/show_bug.cgi?id=1970491","https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html","https://lists.debian.org/debian-lts-announce/2023/03/msg00013.html","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GCKWZWY64EHTOQMLVLTSZ4AA27EWRJMH/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SGPQZFVJCFGDSISFXPCQTTBBD7QZLJKI/"],"products":["debian:debian_linux","fedoraproject:fedora","libslirp_project:libslirp","redhat:enterprise_linux"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-3594","score":0.00326,"percentile":0.2573,"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."]}