Vulnerability · Published Jan 17, 2023 · Assigned by mitre
CVE-2021-36647
Medium 4.7
In plain English
A medium-severity broken cryptography in the mbedtls package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | mbedtls | 2.16.11-0.1 | DEBIAN-CVE-2021-36647 |
| Debian:13 | mbedtls | 2.16.11-0.1 | DEBIAN-CVE-2021-36647 |
| Debian:14 | mbedtls | 2.16.11-0.1 | DEBIAN-CVE-2021-36647 |
Affected products (as reported)
Weakness: CWE-327 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N