{"id":"CVE-2021-34343","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-34343","generatedAt":"2026-10-27T22:33:07.764Z","title":"A stack buffer overflow vulnerability has been reported to affect QNAP device running QTS, QuTScloud, QuTS hero.","description":"A stack buffer overflow vulnerability has been reported to affect QNAP device running QTS, QuTScloud, QuTS hero. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of QTS, QuTScloud, QuTS hero: QTS 4.5.4.1715 build 20210630 and later QTS 5.0.0.1716 build 20210701 and later QuTScloud c4.5.6.1755 and later QuTS hero h4.5.4.1771 build 20210825 and later","published":"2021-09-10T04:15:18.000Z","lastModified":"2026-06-17T03:55:42.000Z","status":"Modified","sourceIdentifier":"security@qnapsecurity.com.tw","cvss":{"version":"3.1","score":7.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-787"],"affected":["qnap/qts","qnap/quts hero","qnap/qutscloud"],"epss":{"score":0.0195,"percentile":0.80088,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.95%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://www.qnap.com/en/security-advisory/qsa-21-33","tags":["Vendor Advisory"],"source":"security@qnapsecurity.com.tw"},{"url":"https://www.qnap.com/en/security-advisory/qsa-21-33","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-34343","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}