CVE-2022-24667: Github.com/apple/swift nio http2 Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-w3f6-pc54-gfw7
CVSS 7.5
CWE-190
Published
Advisory Summary

CVE-2022-24667 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-190: Integer Overflow or Wraparound) affecting Github.com/apple/swift nio http2 libraries in the SwiftURL ecosystem. The issue involves swift-nio-http2 vulnerable to denial of service via mishandled hpack variable length integer encoding. Remediation is available by upgrading affected packages to version 1.19.2.

CVE-2022-24667 at a Glance

CVE Identifier CVE-2022-24667
GHSA Identifier GHSA-w3f6-pc54-gfw7
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-190: Integer Overflow or Wraparound
Affected Product Github.com/apple/swift nio http2
Package Ecosystem SwiftURL
Published Date
Last Updated

Security Impact

CVSS: 7.5

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: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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2022-24667

To remediate this vulnerability, upgrade all affected Github.com/apple/swift nio http2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/apple/swift-nio-http2 fixed: 1.19.2
Upgrade github.com/apple/swift-nio-http2 to 1.19.2
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 github.com/apple/swift-nio-http2

How to Check if You Are Affected

To determine whether your application is affected by CVE-2022-24667, inspect your project dependencies for Github.com/apple/swift nio http2:

inspect dependencies for github.com/apple/swift-nio-http2

Analyze the terminal output to locate any version of Github.com/apple/swift nio http2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.19.2), 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-190: Integer Overflow or Wraparound, where the 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. In Github.com/apple/swift nio http2, 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

A program using swift-nio-http2 is vulnerable to a denial of service attack, caused by a network peer sending a specially crafted HPACK-encoded header block. This attack affects all swift-nio-http2 versions from 1.0.0 to 1.19.1. It is fixed in 1.19.2 and later releases. There are a number of implementation errors in the parsing of HPACK-encoded header blocks that allow maliciously crafted HPACK header blocks to cause crashes in processes using swift-nio-http2. Each of these crashes is triggered instead of an integer overflow. A malicious HPACK header block could be sent on any of the HPACK-carrying frames in a HTTP/2 connection (HEADERS and PUSH_PROMISE), at any position. Sending a HPACK header block does not require any special permission, so any HTTP/2 connection peer may send one. For clients, this means any server to which they connect may launch this attack. For servers, anyone they allow to connect to them may launch such an attack. The attack is low-effort: it takes very little resources to send an appropriately crafted field block. The impact on availability is high: receiving a frame carrying this field block immediately crashes the server, dropping all in-flight connections and causing the service to need to restart. It is straightforward for an attacker to repeatedly send appropriately crafted field blocks, so attackers require very few resources to achieve a substantial denial of service. The attack does not have any confidentiality or integrity risks in and of itself: swift-nio-http2 is parsing the field block in memory-safe code and the crash is triggered instead of an integer overflow. However, sudden process crashes can lead to violations of invariants in services, so it is possible that this attack can be used to trigger an error condition that has confidentiality or integrity risks. The risk can be mitigated if untrusted peers can be prevented from communicating with the service. This mitigation is not available to many services. The issue is fixed by rewriting the parsing code to correctly handle all conditions in the function. The principal issue was found by automated fuzzing by oss-fuzz, but several associated bugs in the same code were found by code audit and fixed at the same time.

CVE-2022-24667 Affected Github.com/apple/swift nio http2 Versions

1 component(s)
Fixed Versions:
1.19.2
Product / Package Ecosystem Affected Versions Fixed Version
github.com/apple/swift-nio-http2
SwiftURL
≥ 1.0.0
< 1.19.2
1.19.2

References

Frequently Asked Questions

What is CVE-2022-24667?
CVE-2022-24667 is a security vulnerability in Github.com/apple/swift nio http2 involving swift-nio-http2 vulnerable to denial of service via mishandled HPACK variable length integer encoding under CWE-190: Integer Overflow or Wraparound.
Which Github.com/apple/swift nio http2 versions are affected?
Affected versions include releases prior to 1.19.2 across affected packages: github.com/apple/swift-nio-http2.
What version fixes CVE-2022-24667?
Upgrading to 1.19.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/apple/swift-nio-http2 affected?
Yes, github.com/apple/swift-nio-http2 is affected in releases prior to 1.19.2. Upgrade your dependency to 1.19.2 or later.
What is the CVSS score of CVE-2022-24667?
CVE-2022-24667 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2022-24667?
CVE-2022-24667 is classified under CWE-190: Integer Overflow or Wraparound (The 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.).
How can I check SwiftURL dependencies for CVE-2022-24667?
Run the dependency tree command: 'inspect dependencies for github.com/apple/swift-nio-http2'. 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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w3f6-pc54-gfw7",
  "modified" : "2023-06-19T16:55:05Z",
  "published" : "2023-05-18T17:28:39Z",
  "aliases" : [ "CVE-2022-24667" ],
  "summary" : "swift-nio-http2 vulnerable to denial of service via mishandled HPACK variable length integer encoding",
  "details" : "A program using swift-nio-http2 is vulnerable to a denial of service attack, caused by a network peer sending a specially crafted HPACK-encoded header block. This attack affects all swift-nio-http2 versions from 1.0.0 to 1.19.1. It is fixed in 1.19.2 and later releases.\n\nThere are a number of implementation errors in the parsing of HPACK-encoded header blocks that allow maliciously crafted HPACK header blocks to cause crashes in processes using swift-nio-http2. Each of these crashes is triggered instead of an integer overflow.\n\nA malicious HPACK header block could be sent on any of the HPACK-carrying frames in a HTTP/2 connection (HEADERS and PUSH_PROMISE), at any position.\n\nSending a HPACK header block does not require any special permission, so any HTTP/2 connection peer may send one. For clients, this means any server to which they connect may launch this attack. For servers, anyone they allow to connect to them may launch such an attack.\n\nThe attack is low-effort: it takes very little resources to send an appropriately crafted field block. The impact on availability is high: receiving a frame carrying this field block immediately crashes the server, dropping all in-flight connections and causing the service to need to restart. It is straightforward for an attacker to repeatedly send appropriately crafted field blocks, so attackers require very few resources to achieve a substantial denial of service.\n\nThe attack does not have any confidentiality or integrity risks in and of itself: swift-nio-http2 is parsing the field block in memory-safe code and the crash is triggered instead of an integer overflow. However, sudden process crashes can lead to violations of invariants in services, so it is possible that this attack can be used to trigger an error condition that has confidentiality or integrity risks.\n\nThe risk can be mitigated if untrusted peers can be prevented from communicating with the service. This mitigation is not available to many services.\n\nThe issue is fixed by rewriting the parsing code to correctly handle all conditions in the function. The principal issue was found by automated fuzzing by oss-fuzz, but several associated bugs in the same code were found by code audit and fixed at the same time.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "SwiftURL",
      "name" : "github.com/apple/swift-nio-http2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.0"
      }, {
        "fixed" : "1.19.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/apple/swift-nio-http2/security/advisories/GHSA-w3f6-pc54-gfw7"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2022-24667"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apple/swift-nio-http2/commit/56c60a29b1207a731be62fb68cc98246942145ed"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/apple/swift-nio-http2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apple/swift-nio-http2/releases/tag/1.19.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-190" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-05-18T17:28:39Z",
    "nvd_published_at" : null
  }
}