Ecosyste.ms: Advisories

Security Advisories: GSA_kwCzR0hTQS00dnI5LThjamYtdmY5Y80Waw

Async-h1 request smuggling possible with long unread bodies

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
• Contact a core team member on zulip or discord

Permalink: https://github.com/advisories/GHSA-4vr9-8cjf-vf9c
JSON: https://advisories.ecosyste.ms/api/v1/advisories/GSA_kwCzR0hTQS00dnI5LThjamYtdmY5Y80Waw
Source: GitHub Advisory Database
Origin: Unspecified
Severity: Moderate
Classification: General
Published: over 3 years ago
Updated: almost 2 years ago

CVSS Score: 6.8
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

EPSS Percentage: 0.00071
EPSS Percentile: 0.3251

Identifiers: GHSA-4vr9-8cjf-vf9c, CVE-2020-26281
References:

• https://github.com/http-rs/async-h1/security/advisories/GHSA-4vr9-8cjf-vf9c
• https://nvd.nist.gov/vuln/detail/CVE-2020-26281
• https://github.com/http-rs/async-h1/releases/tag/v2.3.0
• https://rustsec.org/advisories/RUSTSEC-2020-0093.html
• https://github.com/advisories/GHSA-4vr9-8cjf-vf9c

Repository: https://github.com/http-rs/async-h1
Blast Radius: 18.7

Affected Packages