CVE-2020-26281 Information

Description

async-h1 is an asynchronous HTTP/1.1 parser for Rust (crates.io). There is a request smuggling vulnerability in async-h1 before version 2.3.0. This vulnerability affects any webserver that uses async-h1 behind a reverse proxy including all such Tide applications. If the server does not read the body of a request which is longer than some buffer length async-h1 will attempt to read a subsequent request from the body content starting at that offset into the body. One way to exploit this vulnerability would be for an adversary to craft a request such that the body contains a request that would not be noticed by a reverse proxy allowing it to forge forwarded/x-forwarded headers. If an application trusted the authenticity of these headers it could be misled by the smuggled request. Another potential concern with this vulnerability is that if a reverse proxy is sending multiple http clients’ requests along the same keep-alive connection it would be possible for the smuggled request to specify a long content and capture another user’s request in its body. This content could be captured in a post request to an endpoint that allows the content to be subsequently retrieved by the adversary. This has been addressed in async-h1 2.3.0 and previous versions have been yanked.

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N

Reference

https://github.com/http-rs/async-h1/security/advisories/GHSA-4vr9-8cjf-vf9c https://github.com/http-rs/async-h1/releases/tag/v2.3.0

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

LOW

Availability Impact

HIGH

Base Score

NONE

Base Severity

7.5