SB2021111134 - Red Hat Enterprise Linux 8 update for gnutls and nettle



SB2021111134 - Red Hat Enterprise Linux 8 update for gnutls and nettle

Published: November 11, 2021

Security Bulletin ID SB2021111134
Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 33% Low 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 secuirty vulnerabilities.


1) Input validation error (CVE-ID: CVE-2021-3580)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists in nettle's RSA decryption functions due to insufficient validation of certain ciphertexts. A remote attacker can send specially crafted  data to the server and perform a denial of service (DoS) attack.


2) Use-after-free (CVE-ID: CVE-2021-20232)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in client_send_params in lib/ext/pre_shared_key.c. A remote attacker can trick the victim to connect to a malicious server using a large Client Hello message over TLS 1.3, trigger a use-after-free error and crash the application or execute arbitrary code on the system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.


3) Use-after-free (CVE-ID: CVE-2021-20231)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in client sending key_share extension. A remote attacker can trick the victim to connect to a malicious server using a large Client Hello message over TLS 1.3, trigger a use-after-free error and crash the application or execute arbitrary code on the system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.


Remediation

Install update from vendor's website.