CVE-2018-3718: Serve Remote Code Execution Vulnerability

MODERATE
Advisory Identifier: GHSA-5rc4-8qqh-vq7f
Share
CVSS 5.3
CWE-177
Published
Advisory Summary

CVE-2018-3718 is a MODERATE (CVSS 5.3) remote code execution vulnerability (CWE-177: Improper Handling of URL Encoding (Hex Encoding)) affecting Serve libraries in the npm ecosystem. The issue involves vercel/serve allows access to restricted files if filename is url encoded.. Remediation is available by upgrading affected packages to version 6.5.2.

CVE-2018-3718 at a Glance

CVE Identifier CVE-2018-3718
GHSA Identifier GHSA-5rc4-8qqh-vq7f
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-177: Improper Handling of URL Encoding (Hex Encoding)
Affected Product Serve
Package Ecosystem npm
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:L/I:N/A:N).

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

How to Fix CVE-2018-3718

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

serve fixed: 6.5.2 
npm install serve@6.5.2
Verify Direct and Transitive Dependencies

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

npm ls serve

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2018-3718, inspect your project dependencies using npm:

npm ls serve

Analyze the terminal output to locate any version of Serve in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.5.2), your application is affected.

Note: The npm ls serve command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-177: Improper Handling of URL Encoding (Hex Encoding), where the product does not properly handle when all or part of an input has been url encoded. In Serve, 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

serve node module suffers from Improper Handling of URL Encoding by permitting access to ignored files if a filename is URL encoded.

CVE-2018-3718 Affected Serve Versions

1 component(s)
Fixed Versions:
6.5.2
Product / Package Ecosystem Affected Versions Fixed Version
serve
npm/serve
npm
< 6.5.2
6.5.2

References

NVD — CVE-2018-3718 NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-3718
hackerone.com/reports/308721 WEB
https://hackerone.com/reports/308721
Serve Source Repository REPOSITORY
https://github.com/vercel/serve

Frequently Asked Questions

What is CVE-2018-3718?
CVE-2018-3718 is a security vulnerability in Serve involving vercel/serve allows access to restricted files if filename is URL encoded. under CWE-177: Improper Handling of URL Encoding (Hex Encoding).
Which Serve versions are affected?
Affected versions include releases prior to 6.5.2 across affected packages: serve.
What version fixes CVE-2018-3718?
Upgrading to 6.5.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is serve affected?
Yes, serve is affected in releases prior to 6.5.2. Upgrade your dependency to 6.5.2 or later.
What is the CVSS score of CVE-2018-3718?
CVE-2018-3718 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:L/I:N/A:N.
What CWE is associated with CVE-2018-3718?
CVE-2018-3718 is classified under CWE-177: Improper Handling of URL Encoding (Hex Encoding) (The product does not properly handle when all or part of an input has been URL encoded.).
How can I check npm dependencies for CVE-2018-3718?
Run the dependency tree command: 'npm ls serve'. 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-5rc4-8qqh-vq7f",
  "modified" : "2023-09-12T20:58:59Z",
  "published" : "2021-08-09T22:24:26Z",
  "aliases" : [ "CVE-2018-3718" ],
  "summary" : "vercel/serve allows access to restricted files if filename is URL encoded.",
  "details" : "serve node module suffers from Improper Handling of URL Encoding by permitting access to ignored files if a filename is URL encoded.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "serve"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.5.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2018-3718"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/308721"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/vercel/serve"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-177" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-09T22:24:10Z",
    "nvd_published_at" : "2018-06-07T02:29:00Z"
  }
}