CVE-2021-32714 Integer Overflow in Chunked Transfer-Encoding

2021-07-0719:35:10

CWE-190

GitHub_M

www.cve.org

5.9 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

9.5 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

45.3%

JSON

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.

CNA Affected

[
  {
    "product": "hyper",
    "vendor": "hyperium",
    "versions": [
      {
        "status": "affected",
        "version": "< 0.14.10"
      }
    ]
  }
]