CVE-2021-32714: Integer Overflow in Chunked Transfer-Encoding
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.
Other sources
Integer Overflow in Chunked Transfer-Encoding
— Microsoft
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2021-32714?
CVE-2021-32714 is considered to have a moderate severity level due to the potential for data loss.
How do I fix CVE-2021-32714?
To fix CVE-2021-32714, upgrade hyper to version 0.14.10 or later.
What versions of hyper are affected by CVE-2021-32714?
CVE-2021-32714 affects hyper versions prior to 0.14.10.
What issues does CVE-2021-32714 cause?
CVE-2021-32714 can lead to integer overflow and potential data loss when decoding large chunk sizes.
Is there a workaround for CVE-2021-32714?
There is no documented workaround for CVE-2021-32714 other than updating to the patched version.