CVE-2021-45105
Publication date 19 December 2021
Last updated 26 August 2025
Ubuntu priority
Cvss 3 Severity Score
Description
Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.
Status
| Package | Ubuntu Release | Status | 
|---|---|---|
| apache-log4j2 | 25.10 questing | 
                                Not affected 
                                
                               | 
| 25.04 plucky | 
                                Not affected 
                                
                               | |
| 24.04 LTS noble | 
                                Not affected 
                                
                               | |
| 22.04 LTS jammy | 
                                Not affected 
                                
                               | |
| 20.04 LTS focal | 
                                Fixed 2.17.0-0.20.04.1 
                                
                               | |
| 18.04 LTS bionic | 
                                Fixed 2.12.4-0ubuntu0.1 
                                
                               | |
| 16.04 LTS xenial | 
                                Vulnerable 
                                
                               | 
Severity score breakdown
| Parameter | Value | 
|---|---|
| Base score |  | 
| Attack vector | Network | 
| Attack complexity | High | 
| Privileges required | None | 
| User interaction | None | 
| Scope | Unchanged | 
| Confidentiality | None | 
| Integrity impact | None | 
| Availability impact | High | 
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | 
References
Related Ubuntu Security Notices (USN)
- USN-5203-1
- Apache Log4j 2 vulnerability
- 19 December 2021
- USN-5222-1
- Apache Log4j 2 vulnerabilities
- 11 January 2022