SB2018121303 - OpenSUSE Linux update for mozilla-nss



SB2018121303 - OpenSUSE Linux update for mozilla-nss

Published: December 13, 2018

Security Bulletin ID SB2018121303
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Man-in-the-middle attack (CVE-ID: CVE-2018-12384)

CWE-ID: CWE-300 - Channel Accessible by Non-Endpoint ('Man-in-the-Middle')

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 conduct man-in-the-middle attack on the target system.

The weakness exists due to ServerHello.random is all zero when handling a v2-compatible ClientHello. A remote attacker can use man-in-the-middle techniques to conduct passive replay attack and obtain potentially sensitive information.


2) Cache Attacks (CVE-ID: CVE-2018-12404)

CWE-ID: CWE-300 - Channel Accessible by Non-Endpoint ('Man-in-the-Middle')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P/U:Green


The vulnerability allows a remote attacker to perform a downgrade attack on the server and decrypt private keys on the target system.

The vulnerability exists due to a core weakness in TLS that relates to the handshaking of the session key which is used within the tunnel during parallelisation of thousands of oracle queries that occurs using a cluster of TLS servers which share the same public key certificate. A remote attacker can mount a microarchitectural side channel attack against a vulnerable implementation, obtain a network man-in-the-middle position, obtain the relevant data to sign and trigger the victim server to decrypt ciphertexts chosen by the adversary to perform a downgrade attack.







Remediation

Install update from vendor's website.