GHSA-q6cp-qfwq-4gcv: H2 H2 Servers Vulnerable To Degradation Vulnerability

MODERATE
Share
CVSS 5.3
CWE-400 CWE-770
Published
Advisory Summary

GHSA-q6cp-qfwq-4gcv is a MODERATE (CVSS 5.3) h2 servers vulnerable to degradation vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting H2 libraries in the crates.io ecosystem. The issue involves h2 servers vulnerable to degradation of service with continuation flood. Remediation is available by upgrading affected packages to version 0.3.26, 0.4.4.

GHSA-q6cp-qfwq-4gcv at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-q6cp-qfwq-4gcv
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product H2
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 5.3

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:N/I:N/A:L).

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 None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix GHSA-q6cp-qfwq-4gcv

To remediate this vulnerability, upgrade all affected H2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

h2 fixed: 0.3.26 
Upgrade h2 to 0.3.26
h2 fixed: 0.4.4 
Upgrade h2 to 0.4.4
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 h2

How to Check if You Are Affected

To determine whether your application is affected by GHSA-q6cp-qfwq-4gcv, inspect your project dependencies for H2:

inspect dependencies for h2

Analyze the terminal output to locate any version of H2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.26), 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-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In H2, 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

An attacker can send a flood of CONTINUATION frames, causing `h2` to process them indefinitely. This results in an increase in CPU usage. Tokio task budget helps prevent this from a complete denial-of-service, as the server can still respond to legitimate requests, albeit with increased latency. More details at https://seanmonstar.com/blog/hyper-http2-continuation-flood/. Patches available for 0.4.x and 0.3.x versions.

GHSA-q6cp-qfwq-4gcv Affected H2 Versions

2 component(s)
Fixed Versions:
0.3.260.4.4
Product / Package Ecosystem Affected Versions Fixed Version
h2
 crates.io
< 0.3.26
0.3.26
h2
 crates.io
≥ 0.4.0
< 0.4.4
0.4.4

References

H2 Source Repository REPOSITORY
https://github.com/hyperium/h2
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2024-0332.html
seanmonstar.com/blog/hyper-http2-co... WEB
https://seanmonstar.com/blog/hyper-http2-continuation-flood
www.kb.cert.org/vuls/id/421644 WEB
https://www.kb.cert.org/vuls/id/421644

Frequently Asked Questions

What is GHSA-q6cp-qfwq-4gcv?
GHSA-q6cp-qfwq-4gcv is a security vulnerability in H2 involving h2 servers vulnerable to degradation of service with CONTINUATION Flood under CWE-400: Uncontrolled Resource Consumption.
Which H2 versions are affected?
Affected versions include releases prior to 0.3.26, 0.4.4 across affected packages: h2.
What version fixes GHSA-q6cp-qfwq-4gcv?
Upgrading to 0.3.26, 0.4.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is h2 affected?
Yes, h2 is affected in releases prior to 0.3.26, 0.4.4. Upgrade your dependency to 0.3.26, 0.4.4 or later.
What is the CVSS score of GHSA-q6cp-qfwq-4gcv?
GHSA-q6cp-qfwq-4gcv has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with GHSA-q6cp-qfwq-4gcv?
GHSA-q6cp-qfwq-4gcv is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check crates.io dependencies for GHSA-q6cp-qfwq-4gcv?
Run the dependency tree command: 'inspect dependencies for h2'. 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-q6cp-qfwq-4gcv",
  "modified" : "2024-04-05T15:05:32Z",
  "published" : "2024-04-05T15:05:32Z",
  "aliases" : [ ],
  "summary" : "h2 servers vulnerable to degradation of service with CONTINUATION Flood",
  "details" : "An attacker can send a flood of CONTINUATION frames, causing `h2` to process them indefinitely. This results in an increase in CPU usage.\n\nTokio task budget helps prevent this from a complete denial-of-service, as the server can still respond to legitimate requests, albeit with increased latency.\n\nMore details at https://seanmonstar.com/blog/hyper-http2-continuation-flood/.\n\nPatches available for 0.4.x and 0.3.x versions.\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "h2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.26"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "h2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.4.0"
      }, {
        "fixed" : "0.4.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "PACKAGE",
    "url" : "https://github.com/hyperium/h2"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2024-0332.html"
  }, {
    "type" : "WEB",
    "url" : "https://seanmonstar.com/blog/hyper-http2-continuation-flood"
  }, {
    "type" : "WEB",
    "url" : "https://www.kb.cert.org/vuls/id/421644"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-05T15:05:32Z",
    "nvd_published_at" : null
  }
}