CVE-2019-12519
Publication date 15 April 2020
Last updated 25 August 2025
Ubuntu priority
Cvss 3 Severity Score
Description
An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's being evaluated. When processing the expression, it could either evaluate the top of the stack, or add a new member to the stack. When adding a new member, there is no check to ensure that the stack won't overflow.
Status
| Package | Ubuntu Release | Status | 
|---|---|---|
| squid | ||
| 20.04 LTS focal | 
                                Fixed 4.10-1ubuntu1.1 
                                
                               | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| squid3 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | 
                                Fixed 3.5.27-1ubuntu1.6 
                                
                               | |
| 16.04 LTS xenial | 
                                Fixed 3.5.12-1ubuntu7.11 
                                
                               | |
| 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 | Low | 
| Privileges required | None | 
| User interaction | None | 
| Scope | Unchanged | 
| Confidentiality | High | 
| Integrity impact | High | 
| Availability impact | High | 
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | 
References
Related Ubuntu Security Notices (USN)
- USN-4356-1
- Squid vulnerabilities
- 13 May 2020