CVE-2021-28116
Publication date 9 March 2021
Last updated 18 August 2025
Ubuntu priority
Cvss 3 Severity Score
Description
Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code execution as nobody.
Status
| Package | Ubuntu Release | Status | 
|---|---|---|
| squid | 25.10 questing | 
                                Fixed 4.13-10ubuntu5 
                                
                               | 
| 25.04 plucky | 
                                Fixed 4.13-10ubuntu5 
                                
                               | |
| 24.04 LTS noble | 
                                Fixed 4.13-10ubuntu5 
                                
                               | |
| 22.04 LTS jammy | 
                                Fixed 4.13-10ubuntu5 
                                
                               | |
| 20.04 LTS focal | 
                                Fixed 4.10-1ubuntu1.5 
                                
                               | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| squid3 | 25.10 questing | Not in release | 
| 25.04 plucky | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | 
                                Fixed 3.5.27-1ubuntu1.12 
                                
                               | |
| 16.04 LTS xenial | 
                                Vulnerable 
                                
                               | |
| 14.04 LTS trusty | Not in release | 
Patch details
| Package | Patch details | 
|---|---|
| squid | 
Severity score breakdown
| Parameter | Value | 
|---|---|
| Base score |  | 
| Attack vector | Network | 
| Attack complexity | High | 
| Privileges required | None | 
| User interaction | None | 
| Scope | Unchanged | 
| Confidentiality | Low | 
| Integrity impact | None | 
| Availability impact | None | 
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N | 
References
Related Ubuntu Security Notices (USN)
- USN-5104-1
- Squid vulnerability
- 5 October 2021