SB2018070223 - Fedora 27 update for botan2



SB2018070223 - Fedora 27 update for botan2

Published: July 2, 2018 Updated: April 24, 2025

Security Bulletin ID SB2018070223
Severity
Low
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Memory-cache side-channel attack (CVE-ID: CVE-2018-0495)

The vulnerability allows a local attacker to obtain potentially sensitive information.

The vulnerability exists due to a leakage of information through memory caches when the affected library uses a private key to create Elliptic Curve Digital Signature Algorithm (ECDSA) signatures.  A local attacker can conduct a memory-cache side-channel attack on ECDSA signatures and recover sensitive information, such as ECDSA private keys, which could be used to conduct further attacks. 

Note: The vulnerability is known as the "Return Of the Hidden Number Problem" or ROHNP.


2) Information disclosure (CVE-ID: CVE-2018-12435)

The vulnerability allows a local attacker to obtain potentially sensitive information.

The vulnerability exists in the Botan library due to a leakage of information through memory caches when the library uses a private key to create Elliptic Curve Digital Signature Algorithm (ECDSA) signatures as demonstrayed in the dsa/dsa.cpp, ec_group/ec_group.cpp, and ecdsa/ecdsa.cpp source code files. A local attacker can conduct a memory-cache side-channel attack and recover sensitive information, such ECDSA private keys, which could be used to conduct further attacks.


Remediation

Install update from vendor's website.