Insufficient Entropy in libtpms - CVE-2021-3505
Published: July 1, 2021
Vulnerability identifier: #VU54502
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-3505
CWE-ID: CWE-331
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Stefan Berger
Affected software:
libtpms
libtpms
Detailed vulnerability description
The vulnerability allows a local user to decrypt data.
The vulnerability exists in the TPM 2 implementation, which returns 2048 bit keys with ~1984 bit strength due to a bug in the TCG specification. The bug is in the key creation algorithm in RsaAdjustPrimeCandidate(), which is called before the prime number check.
How to mitigate CVE-2021-3505
Install updates from vendor's website.