SB2017011002 - ECDSA P-256 private key recovery in OpenSSL
Published: January 10, 2017 Updated: July 5, 2022
Security Bulletin ID
SB2017011002
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Information disclosure (CVE-ID: CVE-2016-7056)
The vulnerability allows a local user obtain potentially sensitive information.The vulnerability exists due the OpenSSL does not properly set the BN_FLG_CONSTTIME for nonces when signing with the P-256 elliptic curve in ecdsa_sign_setup() function in crypto/ec/ecdsa_ossl.c. A local attacker can conduct a cache-timing attack and recover ECDSA P-256 private keys
Successful exploitation of this vulnerability may allow an attacker to obtain potentially sensitive information.
The vulnerability is discovered in OpenSSL 1.0.1u. Other versions may also be affected.
Remediation
Install update from vendor's website.