SB2018092520 - Fedora EPEL 6 update for gnutls30



SB2018092520 - Fedora EPEL 6 update for gnutls30

Published: September 25, 2018 Updated: April 24, 2025

Security Bulletin ID SB2018092520
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Partial DoS

Breakdown by Severity

Medium 25% Low 75%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Null pointer dereference (CVE-ID: CVE-2017-7507)

CWE-ID: CWE-476 - NULL Pointer Dereference

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


The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists due to NULL pointer dereference while decoding a status response TLS extension with valid contents. A remote attacker can send specially crafted status_request extension in a ClientHello message to cause the GnuTLS server application to crash.

Successful exploitation of the vulnerability results in denial of service.

2) Use of a broken or risky cryptographic algorithm (CVE-ID: CVE-2018-10844)

CWE-ID: CWE-327 - Use of a Broken or Risky Cryptographic Algorithm

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 due to usage of an insecure implementation of HMAC-SHA-256 algorithm vulnerable to a Lucky thirteen style attack. A remote attacker with ability to intercept traffic can recover encrypted data.


3) Use of a broken or risky cryptographic algorithm (CVE-ID: CVE-2018-10845)

CWE-ID: CWE-327 - Use of a Broken or Risky Cryptographic Algorithm

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 due to usage of an insecure implementation of HMAC-SHA-384 algorithm vulnerable to a Lucky thirteen style attack. A remote attacker with ability to intercept traffic can recover encrypted data.


4) Cryptographic issues (CVE-ID: CVE-2018-10846)

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 due to a cache-based side channel in GnuTLS implementation that can lead to recovery of data in cross-VM attack setting. A remote attacker with ability to intercept traffic can recover encrypted data using a combination of "Just in Time" Prime+probe attack in combination with Lucky-13 attack.


Remediation

Install update from vendor's website.