CVE-2020-26303: Insane Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-w455-mfq9-hf74
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CVSS 7.5
CWE-1333
Published
Advisory Summary

CVE-2020-26303 is a MODERATE (CVSS 7.5) denial of service vulnerability (CWE-1333: Inefficient Regular Expression Complexity) affecting Insane libraries in the npm ecosystem. The issue involves insane vulnerable to regular expression denial of service. Remediation is available in the latest vendor maintenance releases.

CVE-2020-26303 at a Glance

CVE Identifier CVE-2020-26303
GHSA Identifier GHSA-w455-mfq9-hf74
Severity MODERATE
CVSS v3.1 Base Score 7.5
CWE Classification CWE-1333: Inefficient Regular Expression Complexity
Affected Product Insane
Package Ecosystem npm
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-2020-26303

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

insane fixed: Latest secure release 
npm install insane@Latest secure release
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 insane

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-26303, inspect your project dependencies using npm:

npm ls insane

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

Note: The npm ls insane 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-1333: Inefficient Regular Expression Complexity, where the product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. In Insane, 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

insane is a whitelist-oriented HTML sanitizer. Versions 2.6.2 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). As of time of publication, no known patches are available.

CVE-2020-26303 Affected Insane Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
insane
npm/insane
npm
≤ 2.6.2

References

NVD — CVE-2020-26303 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-26303
Insane Source Repository REPOSITORY
https://github.com/bevacqua/insane/issues/19
Insane Source Repository REPOSITORY
https://github.com/bevacqua/insane
GitHub Advisory / Wiki ADVISORY
https://securitylab.github.com/advisories/GHSL-2020-289-redos-insane

Frequently Asked Questions

What is CVE-2020-26303?
CVE-2020-26303 is a security vulnerability in Insane involving insane vulnerable to Regular Expression Denial of Service under CWE-1333: Inefficient Regular Expression Complexity.
Which Insane versions are affected?
Affected versions include releases prior to current release patches across affected packages: insane.
What version fixes CVE-2020-26303?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is insane affected?
Yes, insane is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2020-26303?
CVE-2020-26303 has a CVSS v3.1 base score of 7.5 (MODERATE) 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-2020-26303?
CVE-2020-26303 is classified under CWE-1333: Inefficient Regular Expression Complexity (The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.).
How can I check npm dependencies for CVE-2020-26303?
Run the dependency tree command: 'npm ls insane'. 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-w455-mfq9-hf74",
  "modified" : "2024-11-13T23:24:39Z",
  "published" : "2024-10-26T21:30:46Z",
  "aliases" : [ "CVE-2020-26303" ],
  "summary" : "insane vulnerable to Regular Expression Denial of Service",
  "details" : "insane is a whitelist-oriented HTML sanitizer. Versions 2.6.2 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). As of time of publication, no known patches are available.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "insane"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.6.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-26303"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bevacqua/insane/issues/19"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/bevacqua/insane"
  }, {
    "type" : "ADVISORY",
    "url" : "https://securitylab.github.com/advisories/GHSL-2020-289-redos-insane"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-10-28T14:40:03Z",
    "nvd_published_at" : "2024-10-26T21:15:13Z"
  }
}