Side channel attack on RSA and static Diffie-Hellman in mbed TLS - #VU46188
Published: September 1, 2020
Vulnerability identifier: #VU46188
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-310
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists due to mbed TLS is using the GCD functio, which is prone to a single-trace side-channel attack. An attacker 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) can recover the private keys used in RSA or static (finite-field) Diffie-Hellman operations.
Affected software
mbed TLS
Remediation
Install updates from vendor's website.
mbed TLS - addressed in versions 2.7.17, 2.16.8, 2.24.0