{"id":"CVE-2021-36647","aliases":["AZL-13023","AZL-47713","DEBIAN-CVE-2021-36647","DLA-4236-1","EUVD-2021-23243","GHSA-7wwm-8prx-hpg2","JLSEC-2025-221","UBUNTU-CVE-2021-36647"],"status":"published","title":"Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum...","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.","severity":{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.00172,"percentile":0.06665,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-327"],"published":"2023-01-17T00:00:00Z","modified":"2026-10-24T10:50:07Z","fixes":[{"ecosystem":"Azure Linux:2","package":"fluent-bit","fixed_in":["2.0.9-1"],"sources":["osv"]},{"ecosystem":"Azure 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Party Advisory","advisory","web","report"]},{"url":"https://github.com/ARMmbed/mbedtls/releases/","tags":["x_transferred","Third Party Advisory","advisory","web","report"]},{"url":"https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1","tags":["x_transferred","Vendor Advisory","advisory","web","report"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/06/msg00034.html","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-36647","tags":["web"]},{"url":"https://github.com/ARMmbed/mbedtls/releases"},{"url":"https://github.com/advisories/GHSA-7wwm-8prx-hpg2"},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-36647","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-36647","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-36647","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-36647","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.","status":"published","published":"2023-01-17T00:00:00Z","modified":"2025-11-03T19:26:11.739Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"adp"}],"cwes":["CWE-327"],"updated_at":"2026-11-02T14:33:05.989686Z"}],"euvd":[{"id":"EUVD-2021-23243","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.","status":"published","published":"2023-01-17T00:00:00Z","modified":"2025-11-03T19:26:11Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T19:49:34.152725Z"}],"ghsa":[{"id":"GHSA-7wwm-8prx-hpg2","title":"Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum...","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.","status":"published","published":"2023-01-17T21:30:21Z","modified":"2025-11-03T21:30:47Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-327"],"updated_at":"2026-11-02T15:04:18.176646Z"}],"nvd":[{"id":"CVE-2021-36647","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.","status":"published","published":"2023-01-17T21:15:10.88Z","modified":"2026-06-17T03:58:59.387Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"},{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-327"],"updated_at":"2026-11-02T14:07:07.323379Z"}],"osv":[{"id":"AZL-13023","title":"CVE-2021-36647 affecting package fluent-bit for versions less than 2.0.9-1","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.","status":"published","published":"2023-01-17T21:15:10Z","modified":"2026-04-21T04:22:33.603611Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:28:02.666535Z"},{"id":"AZL-47713","title":"CVE-2021-36647 affecting package hvloader for versions less than 1.0.1-6","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.","status":"published","published":"2023-01-17T21:15:10Z","modified":"2026-04-21T04:32:59.052863Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:28:05.694722Z"},{"id":"CVE-2021-36647","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.","status":"published","published":"2023-01-17T21:15:10.88Z","modified":"2026-10-24T10:50:07.968996972Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:20.434873Z"},{"id":"DEBIAN-CVE-2021-36647","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.","status":"published","published":"2023-01-17T21:15:10.88Z","modified":"2026-10-23T18:05:22.893376793Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:35.233346Z"},{"id":"JLSEC-2025-221","title":"Use of a Broken or Risky Cryptographic Algorithm in the function `mbedtls_mpi_exp_mod()` in lignum.c...","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.","status":"published","published":"2025-11-21T15:59:04.054Z","modified":"2026-07-23T22:30:20.01614361Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:47:17.805107Z"},{"id":"UBUNTU-CVE-2021-36647","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.","status":"published","published":"2023-01-17T21:15:00Z","modified":"2026-04-22T12:57:13.166506Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"},{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:54:27.870979Z"},{"id":"DLA-4236-1","title":"mbedtls - security update","status":"published","published":"2025-06-30T00:00:00Z","modified":"2026-03-09T02:10:22.793566Z","updated_at":"2026-11-02T15:46:12.7027Z"}]}}