PT-2020-17573 · Rust · Async-H1
Published
2020-12-17
·
Updated
2022-05-24
·
CVE-2020-36202
CVSS v3.1
6.1
Medium
| Vector | AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Name of the Vulnerable Software and Affected Versions
async-h1 versions prior to 2.3.0
Description
An issue was discovered in the async-h1 crate that allows request smuggling to occur when used behind a reverse proxy. This 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. This can be exploited by 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 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.
Recommendations
For versions prior to 2.3.0, update to version 2.3.0 or later to address the issue. As a temporary workaround, consider restricting the use of async-h1 behind a reverse proxy until a patch is applied. Avoid using async-h1 in configurations where request smuggling could be exploited, such as behind a reverse proxy with multiple http clients' requests along the same keep-alive connection.
Fix
HTTP Request/Response Smuggling
XSS
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Related Identifiers
Affected Products
Async-H1