CVE-2021-32714: hyper Integer Overflow or Wraparound

Vulnerability summary

CVE-2021-32714 is a critical (CVSS 9.1) Integer Overflow or Wraparound vulnerability in hyper. EPSS estimates a 1.16% chance of exploitation in the next 30 days, higher than 66.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 07-07-2021
   PublishedVulnerability first disclosed.
2. 03-08-2024
   Last modifiedVulnerability information updated.

Description

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.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.