CVE-2021-36647

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)
References	DLA-4236-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
mbedtls (PTS)	bullseye	2.16.9-0.1	vulnerable
	bullseye (security)	2.16.9-0.1+deb11u1	fixed
	bookworm	2.28.3-1	fixed
	trixie	3.6.3-1	fixed
	sid	3.6.4-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
mbedtls	source	bullseye	2.16.9-0.1+deb11u1		DLA-4236-1
mbedtls	source	(unstable)	2.16.11-0.1

Notes

[buster] - mbedtls <no-dsa> (Minor issue)
https://mbed-tls.readthedocs.io/en/latest/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1/