Use of a broken or risky cryptographic algorithm in mbedtls (Alpine package)

1) Use of a broken or risky cryptographic algorithm

EUVDB-ID: #VU29653

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-10932

CWE-ID: CWE-327 - Use of a Broken or Risky Cryptographic Algorithm

Exploit availability: No

Description

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

The vulnerability exists due to incorrect implementation of modular inverse operation as implemented in Mbed TLS. 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 fully recover an ECDSA private key after observing a number of signature operations a.k.k. single-trace side channel attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

mbedtls (Alpine package): 2.16.5-r0

External links

http://git.alpinelinux.org/aports/commit/?id=0da4df68b1d14ddc4a8e3e8620e39be0d1746512
http://git.alpinelinux.org/aports/commit/?id=dbc63cb20c6d689ff9656e9b5856c7d994e09b94
http://git.alpinelinux.org/aports/commit/?id=e9adc65cdc1f79a5de1831fff0c5833b540665d2

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.