{"id":"CVE-2021-36647","state":"PUBLISHED","title":"Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attacker","description":"Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attackers with access to precise enough timing and memory access information (typically an untrusted operating system attacking a secure enclave such as SGX or the TrustZone secure world) to recover the private keys used in RSA.","publishedAt":"2023-01-17T00:00:00.000Z","updatedAt":"2025-11-03T19:26:11.739Z","severity":{"score":4.7,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","source":"CISA-ADP"},"assigner":"mitre","products":["n/a n/a"],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":["https://kouzili.com/Load-Step.pdf","https://github.com/ARMmbed/mbedtls/releases/","https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1","https://lists.debian.org/debian-lts-announce/2025/06/msg00034.html"],"weaknesses":["CWE-327"],"ingestedAt":"2026-10-29T19:48:44.655Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/36xxx/CVE-2021-36647.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-36647","state":"PUBLISHED","datePublished":"2023-01-17T00:00:00.000Z","dateUpdated":"2025-11-03T19:26:11.739Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2021-07-12T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attackers with access to precise enough timing and memory access information (typically an untrusted operating system attacking a secure enclave such as SGX or the TrustZone secure world) to recover the private keys used in RSA."}],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":[{"url":"https://kouzili.com/Load-Step.pdf"},{"url":"https://github.com/ARMmbed/mbedtls/releases/"},{"url":"https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1"}],"problemTypes":[{"descriptions":[{"type":"text","lang":"en","description":"n/a"}]}],"providerMetadata":{"shortName":"mitre","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateUpdated":"2023-01-17T00:00:00.000Z"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://kouzili.com/Load-Step.pdf","tags":["x_transferred"]},{"url":"https://github.com/ARMmbed/mbedtls/releases/","tags":["x_transferred"]},{"url":"https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1","tags":["x_transferred"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/06/msg00034.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T19:26:11.739Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":4.7,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"HIGH","availabilityImpact":"NONE","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2025-04-08T20:30:16.965859Z","id":"CVE-2021-36647","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-327","type":"CWE","lang":"en","description":"CWE-327 Use of a Broken or Risky Cryptographic Algorithm"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-04-08T20:31:32.007Z"}}]}}}