Private key recovery in crypto++

1) Covert Timing Channel

EUVDB-ID: #VU23452

Risk: Low

CVSSv3.1: 2.2 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-48570,CVE-2019-14318

CWE-ID: CWE-385 - Covert Timing Channel

Exploit availability: No

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to scalar multiplication in ecp.cpp (prime field curves, small leakage) and algebra.cpp (binary field curves, large leakage) is not constant time and leaks the bit length of the scalar among other information within the timing side channel in ECDSA signature generation. A local user with ability to measure the duration of hundreds to thousands of signing operations can compute the private key used.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Crypto++: 5.0 - 8.4.0

External links

http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00066.html
http://eprint.iacr.org/2011/232.pdf
http://github.com/weidai11/cryptopp/issues/869
http://tches.iacr.org/index.php/TCHES/article/view/7337
http://github.com/weidai11/cryptopp/releases/tag/CRYPTOPP_8_3_0
http://github.com/weidai11/cryptopp/releases/tag/CRYPTOPP_8_4_0

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.