GHSA-4vr9-8cjf-vf9c

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    GHSA-4vr9-8cjf-vf9c

    Published: 12 Oct 2021Last Modified: 10 Sept 2026

    Summary: Async-h1 request smuggling possible with long unread bodies

    Details: ### Impact 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. ### Patches This has been addressed in async-h1 2.3.0 and previous versions have been yanked. ### Workarounds none ### References https://github.com/http-rs/async-h1/releases/tag/v2.3.0 ### For more information If you have any questions or comments about this advisory: * Open an issue in [async-h1](https://github.com/http-rs/async-h1) * Contact a core team member on [zulip](https://http-rs.zulip-chat.com) or [discord](https://discord.gg/x2gKzst)

    Affected packages

    Package

    Name: async-h1

    Purl: pkg:cargo/async-h1

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 0
    Fixed -2.3.0

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    GHSA-4vr9-8cjf-vf9c | CVE-DB