CVE-2021-40346
Publication date 7 September 2021
Last updated 25 August 2025
Ubuntu priority
Description
An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, allowing an attacker to bypass all configured http-request HAProxy ACLs and possibly other ACLs.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| haproxy | 22.04 LTS jammy |
Fixed 2.2.9-2ubuntu2
|
| 20.04 LTS focal |
Fixed 2.0.13-2ubuntu0.3
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Not in release |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
7.5 · High
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | High |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
References
Related Ubuntu Security Notices (USN)
- USN-5063-1
- HAProxy vulnerabilities
- 8 September 2021