| Name | 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| mbedtls (PTS) | stretch (security), stretch (lts), stretch | 2.4.2-1+deb9u4 | vulnerable |
| buster (security), buster, buster (lts) | 2.16.9-0~deb10u1 | vulnerable |
| bullseye | 2.16.9-0.1 | vulnerable |
| bookworm | 2.28.3-1 | fixed |
| trixie | 2.28.8-1 | fixed |
| sid | 3.6.2-3 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| mbedtls | source | stretch | (unfixed) | end-of-life | | |
| mbedtls | source | (unstable) | 2.16.11-0.1 | | | |
Notes
[bullseye] - mbedtls <no-dsa> (Minor issue)
[buster] - mbedtls <no-dsa> (Minor issue)
https://mbed-tls.readthedocs.io/en/latest/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1/