CVE-2020-35863: Hyper HTTP Request Smuggling Vulnerability

CRITICAL
Advisory Identifier: GHSA-h3qr-rq2j-74w4
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CVSS 9.8
CWE-444
Published
Advisory Summary

CVE-2020-35863 is a CRITICAL (CVSS 9.8) http request smuggling vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Hyper libraries in the crates.io ecosystem. The issue involves http request smuggling in hyper. Remediation is available by upgrading affected packages to version 0.12.34.

CVE-2020-35863 at a Glance

CVE Identifier CVE-2020-35863
GHSA Identifier GHSA-h3qr-rq2j-74w4
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Product Hyper
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2020-35863

To remediate this vulnerability, upgrade all affected Hyper dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

hyper fixed: 0.12.34 
Upgrade hyper to 0.12.34
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for hyper

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35863, inspect your project dependencies for Hyper:

inspect dependencies for hyper

Analyze the terminal output to locate any version of Hyper in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.12.34), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), where 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. In Hyper, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Vulnerable versions of hyper allow GET requests to have bodies, even if there is no Transfer-Encoding or Content-Length header. As per the HTTP 1.1 specification, such requests do not have bodies, so the body will be interpreted as a separate HTTP request. This allows an attacker who can control the body and method of an HTTP request made by hyper to inject a request with headers that would not otherwise be allowed, as demonstrated by sending a malformed HTTP request from a Substrate runtime. This allows bypassing CORS restrictions. In combination with other vulnerabilities, such as an exploitable web server listening on loopback, it may allow remote code execution. The flaw was corrected in hyper version 0.12.34.

CVE-2020-35863 Affected Hyper Versions

1 component(s)
Fixed Versions:
0.12.34
Product / Package Ecosystem Affected Versions Fixed Version
hyper
 crates.io
≥ 0.11.0
< 0.12.34
0.12.34

References

NVD — CVE-2020-35863 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35863
Hyper Source Repository REPOSITORY
https://github.com/hyperium/hyper/issues/1925
Hyper Source Repository REPOSITORY
https://github.com/hyperium/hyper
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0008.html

Frequently Asked Questions

What is CVE-2020-35863?
CVE-2020-35863 is a security vulnerability in Hyper involving HTTP Request Smuggling in hyper under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling').
Which Hyper versions are affected?
Affected versions include releases prior to 0.12.34 across affected packages: hyper.
What version fixes CVE-2020-35863?
Upgrading to 0.12.34 (or the latest patched release for your respective branch) resolves the vulnerability.
Is hyper affected?
Yes, hyper is affected in releases prior to 0.12.34. Upgrade your dependency to 0.12.34 or later.
What is the CVSS score of CVE-2020-35863?
CVE-2020-35863 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2020-35863?
CVE-2020-35863 is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') (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.).
How can I check crates.io dependencies for CVE-2020-35863?
Run the dependency tree command: 'inspect dependencies for hyper'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h3qr-rq2j-74w4",
  "modified" : "2023-06-13T17:40:10Z",
  "published" : "2021-08-25T20:46:08Z",
  "aliases" : [ "CVE-2020-35863" ],
  "summary" : "HTTP Request Smuggling in hyper",
  "details" : "Vulnerable versions of hyper allow GET requests to have bodies, even if there is no Transfer-Encoding or Content-Length header. As per the HTTP 1.1 specification, such requests do not have bodies, so the body will be interpreted as a separate HTTP request.\n\nThis allows an attacker who can control the body and method of an HTTP request made by hyper to inject a request with headers that would not otherwise be allowed, as demonstrated by sending a malformed HTTP request from a Substrate runtime. This allows bypassing CORS restrictions. In combination with other vulnerabilities, such as an exploitable web server listening on loopback, it may allow remote code execution.\n\nThe flaw was corrected in hyper version 0.12.34.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "hyper"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.11.0"
      }, {
        "fixed" : "0.12.34"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35863"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hyperium/hyper/issues/1925"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/hyperium/hyper"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0008.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-444" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T21:20:11Z",
    "nvd_published_at" : null
  }
}