SB2021121538 - Ubuntu update for apache-log4j2



SB2021121538 - Ubuntu update for apache-log4j2

Published: December 15, 2021 Updated: April 14, 2025

Security Bulletin ID SB2021121538
Severity
Critical
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

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

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Code Injection (CVE-ID: CVE-2021-44228)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation when processing LDAP requests. A remote attacker can send a specially crafted request to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, we are aware of attackers exploiting the vulnerability in the wild.


2) Code Injection (CVE-ID: CVE-2021-45046)

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to incomplete patch in Apache Log4j 2.15.0 for a code injection vulnerability #VU58816 (CVE-2021-44228) in certain non-default configurations. A remote attacker with control over Thread Context Map (MDC) input data when the logging configuration uses a non-default Pattern Layout with either a Context Lookup (for example, $${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) can pass malicious data using a JNDI Lookup pattern and perform a denial of service (DoS) attack, exfiltrate data or execute arbitrary code.

Later discovery demonstrates a remote code execution on macOS but no other tested environments.


Remediation

Install update from vendor's website.