CVE-2021-32715
Publication date 7 July 2021
Last updated 26 August 2025
Ubuntu priority
Description
hyper is an HTTP library for rust. hyper's HTTP/1 server code had a flaw that incorrectly parses and accepts requests with a `Content-Length` header with a prefixed plus sign, when it should have been rejected as illegal. This combined with an upstream HTTP proxy that doesn't parse such `Content-Length` headers, but forwards them, can result in "request smuggling" or "desync attacks". The flaw exists in all prior versions of hyper prior to 0.14.10, if built with `rustc` v1.5.0 or newer. The vulnerability is patched in hyper version 0.14.10. Two workarounds exist: One may reject requests manually that contain a plus sign prefix in the `Content-Length` header or ensure any upstream proxy handles `Content-Length` headers with a plus sign prefix.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| rust-hyper | 26.04 LTS resolute |
Not affected
|
| 25.10 questing |
Not affected
|
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal |
Vulnerable
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Not in release |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
3.1 · Low
|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity impact | None |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N |