Cyber Resilience

CVE-2021-32715

LowPublic PoC

Published: 07 July 2021

Published
07 July 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0029 53.2th percentile
Risk Priority 6 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-32715 is a low-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Hyper Hyper. Its CVSS base score is 3.1 (Low).

Operationally, ranked in the top 46.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

hyper is an HTTP library for rust. hyper's HTTP/1 server code had a flaw that incorrectly parses and accepts requests with a `Content-Length` header with a prefixed plus sign, when it should have been rejected as illegal. This combined with…

more

an upstream HTTP proxy that doesn't parse such `Content-Length` headers, but forwards them, can result in "request smuggling" or "desync attacks". The flaw exists in all prior versions of hyper prior to 0.14.10, if built with `rustc` v1.5.0 or newer. The vulnerability is patched in hyper version 0.14.10. Two workarounds exist: One may reject requests manually that contain a plus sign prefix in the `Content-Length` header or ensure any upstream proxy handles `Content-Length` headers with a plus sign prefix.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

hyper
hyper
≤ 0.14.10

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References