{"id":"CVE-2021-42023","aliases":["EUVD-2021-29011","GHSA-x8jw-8x39-62fp"],"status":"published","title":"A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All...","description":"A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All versions). The RSA white-box implementation in affected applications insufficiently protects the built-in private keys that are required to decrypt electronic intellectual property (IP) data in accordance with the IEEE 1735 recommended practice. This could allow a sophisticated attacker to discover the keys, bypassing the protection intended by the IEEE 1735 recommended practice.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.00582,"percentile":0.48294,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":false},"cwes":["CWE-522"],"published":"2021-12-14T00:00:00Z","modified":"2026-06-17T04:09:11Z","exploits":[{"source":"pocgithub","id":"Geeoon/ModelSim-Decryptor","title":"Geeoon/ModelSim-Decryptor","date":"2026-10-10","url":"https://github.com/Geeoon/ModelSim-Decryptor"}],"products":[{"vendor":"siemens","product":"modelsim"},{"vendor":"siemens","product":"modelsim simulation"},{"vendor":"siemens","product":"questa"},{"vendor":"siemens","product":"questa simulation"}],"references":[{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-400332.pdf","tags":["x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-42023"},{"url":"https://github.com/advisories/GHSA-x8jw-8x39-62fp"}],"sources":{"cve":[{"id":"CVE-2021-42023","description":"A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All versions). The RSA white-box implementation in affected applications insufficiently protects the built-in private keys that are required to decrypt electronic intellectual property (IP) data in accordance with the IEEE 1735 recommended practice. This could allow a sophisticated attacker to discover the keys, bypassing the protection intended by the IEEE 1735 recommended practice.","status":"published","published":"2021-12-14T00:00:00Z","modified":"2024-08-04T03:22:25.772Z","cwes":["CWE-522"],"updated_at":"2026-11-02T14:32:58.739039Z"}],"euvd":[{"id":"EUVD-2021-29011","description":"A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All versions). The RSA white-box implementation in affected applications insufficiently protects the built-in private keys that are required to decrypt electronic intellectual property (IP) data in accordance with the IEEE 1735 recommended practice. This could allow a sophisticated attacker to discover the keys, bypassing the protection intended by the IEEE 1735 recommended practice.","status":"published","published":"2021-12-14T00:00:00Z","modified":"2024-08-04T03:22:25Z","updated_at":"2026-11-03T03:24:16.784119Z"}],"ghsa":[{"id":"GHSA-x8jw-8x39-62fp","title":"A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All...","description":"A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All versions). The RSA white-box implementation in affected applications insufficiently protects the built-in private keys that are required to decrypt electronic intellectual property (IP) data in accordance with the IEEE 1735 recommended practice. This could allow a sophisticated attacker to discover the keys, bypassing the protection intended by the IEEE 1735 recommended practice.","status":"published","published":"2021-12-15T00:01:25Z","modified":"2023-02-01T05:06:48Z","cwes":["CWE-522"],"updated_at":"2026-11-02T14:50:25.548742Z"}],"nvd":[{"id":"CVE-2021-42023","description":"A vulnerability has been identified in ModelSim Simulation (All versions), Questa Simulation (All versions). The RSA white-box implementation in affected applications insufficiently protects the built-in private keys that are required to decrypt electronic intellectual property (IP) data in accordance with the IEEE 1735 recommended practice. This could allow a sophisticated attacker to discover the keys, bypassing the protection intended by the IEEE 1735 recommended practice.","status":"published","published":"2021-12-14T12:15:09.917Z","modified":"2026-06-17T04:09:11.597Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":2.1,"vector":"AV:L/AC:L/Au:N/C:P/I:N/A:N","level":"low","assessor":"primary"}],"cwes":["CWE-522"],"updated_at":"2026-11-02T14:07:02.189991Z"}]}}