Vulnerability Details : CVE-2021-32715
Potential exploit
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 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.
Products affected by CVE-2021-32715
- cpe:2.3:a:hyper:hyper:*:*:*:*:*:rust:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-32715
0.30%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 50 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-32715
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
4.3
|
MEDIUM | AV:N/AC:M/Au:N/C:N/I:P/A:N |
8.6
|
2.9
|
NIST | |
|
5.3
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
3.9
|
1.4
|
NIST | |
|
3.1
|
LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N |
1.6
|
1.4
|
GitHub, Inc. |
CWE ids for CVE-2021-32715
-
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.Assigned by:
- nvd@nist.gov (Primary)
- security-advisories@github.com (Secondary)
References for CVE-2021-32715
-
https://github.com/hyperium/hyper/security/advisories/GHSA-f3pg-qwvg-p99c
Lenient Parsing of Content-Length Header When Prefixed with Plus Sign · Advisory · hyperium/hyper · GitHubExploit;Third Party Advisory
-
https://github.com/rust-lang/rust/pull/28826/commits/123a83326fb95366e94a3be1a74775df4db97739
Integer parsing should accept leading plus by arthurprs · Pull Request #28826 · rust-lang/rust · GitHubPatch;Third Party Advisory
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