hyper is an open-source HTTP library for Rust (crates.io). In hyper from version 0.12.0 and before versions 0.13.10 and 0.14.3 there is a vulnerability that can enable a request smuggling attack. The HTTP server code had a flaw that incorre…
Exact source revision recorded 24 Oct 2026 18:22:17 UTC. It does not establish the source's current position. Latest evidence.
euvd · EUVD-2021-1600
Publishedhyper is an open-source HTTP library for Rust (crates.io). In hyper from version 0.12.0 and before versions 0.13.10 and 0.14.3 there is a vulnerability that can enable a request smuggling attack. The HTTP server code had a flaw that incorrectly understands some requests with multiple transfer-encoding headers to have a chunked payload, when it should have been rejected as illegal. This combined with an upstream HTTP proxy that understands the request payload boundary differently can result in "request smuggling" or "desync attacks". To determine if vulnerable, all these things must be true: 1) Using hyper as an HTTP server (the client is not affected), 2) Using HTTP/1.1 (HTTP/2 does not use transfer-encoding), 3) Using a vulnerable HTTP proxy upstream to hyper. If an upstream proxy correctly rejects the illegal transfer-encoding headers, the desync attack cannot succeed. If there is no proxy upstream of hyper, hyper cannot start the desync attack, as the client will repair the headers before forwarding. This is fixed in versions 0.14.3 and 0.13.10. As a workaround one can take the following options: 1) Reject requests that contain a `transfer-encoding` header, 2) Ensure any upstream proxy handles `transfer-encoding` correctly.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Feb 11, 2021, 6:00:18 PM
dateUpdated: Aug 3, 2024, 6:09:15 PM
3 related source bulletins · separate from aliases
openSUSE-SU-2024:12239-1: wayshot-1.1.9-1.1 on GA media
CVE-2021-21299
openSUSE-SU-2024:12274-1: spotifyd-0.3.3-9.1 on GA media
CVE-2021-21299
openSUSE-SU-2024:12238-1: tuigreet-0.7.1-6.1 on GA media
CVE-2021-21299
- Source published
- Feb 11, 2021, 6:00:18 PM (timezone not stated)
- Source modified
- Aug 3, 2024, 6:09:15 PM (timezone not stated)
- Observed here
- 24 Oct 2026 18:22:17 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.
EUVD CVSS 3.1 · 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N