SB2018120612 - Ubuntu update for OpenSSL
Published: December 6, 2018 Updated: December 10, 2018
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Information disclosure (CVE-ID: CVE-2018-0734)
CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local attacker to obtain potentially sensitive information.
The vulnerability exists due to unspecified flaw in Digital Signature Algorithm (DSA). A local attacker can conduct a timing side-channel attack and recover the private key, which could be used to conduct further attacks.
2) Information disclosure (CVE-ID: CVE-2018-0735)
CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a remote attacker to obtain potentially sensitive information.
The vulnerability exists due to disclosure of the OpenSSL ECDSA signature algorithm. A remote attacker can use variations in the signing algorithm to conduct a timing side channel attack and recover the private key.
3) Side-channel attack (CVE-ID: CVE-2018-5407)
CWE-ID: CWE-208 - Information Exposure Through Timing Discrepancy
CVSSv4: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear
The vulnerability allows a physical attacker to obtain potentially sensitive information.
The vulnerability exists due to due to execution of engine sharing on SMT (e.g.Hyper-Threading) architectures when improper handling of information by the processor. A physical attacker can construct a timing side channel to hijack information from processes that are running in the same core.
Note: the vulnerability has been dubbed as PortSmash microarchitecture bug.
Remediation
Install update from vendor's website.