CVE-2021-32714

5.9 MEDIUM 1% exploit odds Fix listed

What it is

hyper is an HTTP library for Rust. In versions prior to 0.14.10, hyper's HTTP server and client code had a flaw that could trigger an integer overflow when decoding chunk sizes that are too big. This allows possible data loss, or if combined with an upstream HTTP proxy that allows chunk sizes larger than hyper does, can result in "request smuggling" or "desync attacks." The vulnerability is patched in version 0.14.10. Two possible workarounds exist. One may reject requests manually that contain a `Transfer-Encoding` header or ensure any upstream proxy rejects `Transfer-Encoding` chunk sizes greater than what fits in 64-bit unsigned integers.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of service disruption.
Exploit odds: 1.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2021-07-07 20:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:53 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 1.2% in the next 30 days (EPSS).
Severity: 5.9 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2021-07-07 20:15 UTC
Last modified: 2026-06-17 03:53 UTC
Exploit probability: 1.2% · EPSS, next 30 days
Weakness: CWE-190 · Integer overflow
Record status: Modified

Affected

Hyper < 0.14.10

Attack profile CVSS 3.1 · 5.9

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Raw vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-32714.md and follow it. Check whether this project is affected by CVE-2021-32714. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record