CVE-2023-50269
Publication date 14 December 2023
Last updated 26 August 2025
Ubuntu priority
Cvss 3 Severity Score
Description
Squid is a caching proxy for the Web. Due to an Uncontrolled Recursion bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5, Squid may be vulnerable to a Denial of Service attack against HTTP Request parsing. This problem allows a remote client to perform Denial of Service attack by sending a large X-Forwarded-For header when the follow_x_forwarded_for feature is configured. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives.
Status
| Package | Ubuntu Release | Status | 
|---|---|---|
| squid | 24.04 LTS noble | 
                                Fixed 6.5-1ubuntu3 
                                
                               | 
| 22.04 LTS jammy | 
                                Fixed 5.7-0ubuntu0.22.04.3 
                                
                               | |
| 20.04 LTS focal | 
                                Fixed 4.10-1ubuntu1.9 
                                
                               | |
| 18.04 LTS bionic | Ignored end of standard support | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Ignored end of standard support | |
| squid3 | 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 3.5.27-1ubuntu1.14+esm2 
                                
                                   | |
| 16.04 LTS xenial | 
                                Fixed 3.5.12-1ubuntu7.16+esm3 
                                
                                   | |
| 14.04 LTS trusty | Ignored end of standard support | 
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| Package | Patch details | 
|---|---|
| squid | 
Severity score breakdown
| Parameter | Value | 
|---|---|
| Base score |  | 
| Attack vector | Network | 
| Attack complexity | Low | 
| Privileges required | None | 
| User interaction | None | 
| Scope | Unchanged | 
| Confidentiality | None | 
| Integrity impact | None | 
| Availability impact | High | 
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | 
References
Related Ubuntu Security Notices (USN)
- USN-6594-1
- Squid vulnerabilities
- 23 January 2024
- USN-6857-1
- Squid vulnerabilities
- 27 June 2024