{"id":"CVE-2021-28484","aliases":["EUVD-2022-0921","GHSA-8m9g-647g-5pxw"],"status":"published","title":"Infinite loop in Yubico yubihsm-connector","description":"An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.01521,"percentile":0.74779,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-835"],"published":"2021-04-14T17:07:26Z","modified":"2026-10-20T10:54:36Z","fixes":[{"ecosystem":"Go","package":"github.com/Yubico/yubihsm-connector","fixed_in":["3.0.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/Yubico/yubihsm-connector","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.1"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/Yubico/yubihsm-connector","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.0.1"}]}]}],"products":[{"vendor":"fedoraproject","product":"fedora"},{"vendor":"yubico","product":"yubihsm_connector"}],"references":[{"url":"https://github.com/Yubico/yubihsm-connector/releases","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://www.yubico.com/support/security-advisories/ysa-2021-02/","tags":["x_refsource_MISC","x_transferred","Vendor Advisory","advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B7Q2KGXSPQEEONAWMFZRVH2TXWX3QPCQ/","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-28484","tags":["advisory"]},{"url":"https://github.com/Yubico/yubihsm-connector/commit/82bdf202c53460bac9106cc9b4b34a0a16cae0ed","tags":["web"]},{"url":"https://github.com/advisories/GHSA-8m9g-647g-5pxw"},{"url":"https://www.yubico.com/support/security-advisories/ysa-2021-02","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2021-28484","description":"An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.","status":"published","published":"2021-04-14T17:07:26Z","modified":"2024-08-03T21:47:32.665Z","updated_at":"2026-11-02T14:33:09.175141Z"}],"euvd":[{"id":"EUVD-2022-0921","description":"An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.","status":"published","published":"2021-04-14T17:07:26Z","modified":"2024-08-03T21:47:32Z","updated_at":"2026-11-03T03:24:46.751124Z"}],"ghsa":[{"id":"GHSA-8m9g-647g-5pxw","title":"Infinite loop in Yubico yubihsm-connector","description":"An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.","status":"published","published":"2022-02-15T01:57:18Z","modified":"2023-02-01T05:05:31Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:R","level":"medium"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T14:36:34.917834Z"}],"nvd":[{"id":"CVE-2021-28484","description":"An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.","status":"published","published":"2021-04-14T18:15:14.44Z","modified":"2026-06-17T03:46:26.923Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T14:06:52.03307Z"}],"osv":[{"id":"CVE-2021-28484","description":"An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.","status":"published","published":"2021-04-14T18:15:14.44Z","modified":"2026-10-20T10:54:36.50984315Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:19.129331Z"},{"id":"GHSA-8m9g-647g-5pxw","title":"Infinite loop in Yubico yubihsm-connector","description":"An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.","status":"published","published":"2022-02-15T01:57:18Z","modified":"2023-11-08T04:05:30.407376Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:R","level":"medium"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T15:46:42.437513Z"}]}}