{"id":"CVE-2021-27217","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-27217","generatedAt":"2026-10-28T02:59:03.512Z","title":"Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout.","description":"An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device. Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout. This could be used by an attacker to cause a client-side denial of service. The yubihsm-shell project is included in the YubiHSM 2 SDK product.","published":"2021-03-04T18:15:14.000Z","lastModified":"2026-06-17T03:44:29.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":4.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-125"],"affected":["yubico/yubihsm-shell"],"epss":{"score":0.01595,"percentile":0.75547,"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":"low","text":"Lower severity and a low EPSS score (1.59%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://blog.inhq.net/posts/yubico-libyubihsm-vuln2","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/Yubico/yubihsm-shell/releases","tags":["Release Notes","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.yubico.com/support/security-advisories/ysa-2021-01/","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://blog.inhq.net/posts/yubico-libyubihsm-vuln2","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/Yubico/yubihsm-shell/releases","tags":["Release Notes","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.yubico.com/support/security-advisories/ysa-2021-01/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-27217","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."}