SB2017070401 - Ubuntu update for Libgcrypt
Published: July 4, 2017
Security Bulletin ID
SB2017070401
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
2
Exploitation vector
Remote access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Side-channel attack (CVE-ID: CVE-2017-7526)
CWE-ID: CWE-310 - Cryptographic Issues
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists in libgcrypt's RSA-1024 implementation using left-to-right method for computing the sliding-window expansion. A remote attacker can perform side-channel attack and gain access to potentially sensitive information.
2) Side-channel attack (CVE-ID: CVE-2017-9526)
CWE-ID: CWE-310 - Cryptographic Issues
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists in libgcrypt's EdDSA implementation. An attacker who learns the EdDSA session key (from side-channel observation during the signing process) can easily recover the long-term secret key.
Remediation
Install update from vendor's website.