CVE-2020-26301: Ssh2 OS Command Injection Vulnerability

HIGH
Advisory Identifier: GHSA-652h-xwhf-q4h6
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CVSS 7.5
CWE-78
Published
Advisory Summary

CVE-2020-26301 is a HIGH (CVSS 7.5) os command injection vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) affecting Ssh2 libraries in the npm ecosystem. The issue involves os command injection in ssh2. Remediation is available by upgrading affected packages to version 1.4.0.

CVE-2020-26301 at a Glance

CVE Identifier CVE-2020-26301
GHSA Identifier GHSA-652h-xwhf-q4h6
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Product Ssh2
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:H/PR:N/UI:N/S:C/C:H/I:L/A:N).

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

How to Fix CVE-2020-26301

To remediate this vulnerability, upgrade all affected Ssh2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

ssh2 fixed: 1.4.0 
npm install ssh2@1.4.0
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 ssh2

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-26301, inspect your project dependencies using npm:

npm ls ssh2

Analyze the terminal output to locate any version of Ssh2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.0), your application is affected.

Note: The npm ls ssh2 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-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), where the product constructs all or part of an os command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended os command when it is sent to a downstream component. In Ssh2, 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

ssh2 is client and server modules written in pure JavaScript for node.js. In ssh2 before version 1.4.0 there is a command injection vulnerability. The issue only exists on Windows. This issue may lead to remote code execution if a client of the library calls the vulnerable method with untrusted input. This is fixed in version 1.4.0.

CVE-2020-26301 Affected Ssh2 Versions

1 component(s)
Fixed Versions:
1.4.0
Product / Package Ecosystem Affected Versions Fixed Version
ssh2
npm/ssh2
npm
< 1.4.0
1.4.0

References

NVD — CVE-2020-26301 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-26301
Security Fix Commit FIX COMMIT
https://github.com/mscdex/ssh2/commit/f763271f41320e71d5cbee02ea5bc6a2ded3ca21
Ssh2 Source Repository REPOSITORY
https://github.com/mscdex/ssh2
GitHub Advisory / Wiki ADVISORY
https://securitylab.github.com/advisories/GHSL-2020-123-mscdex-ssh2
www.npmjs.com/package/ssh2 WEB
https://www.npmjs.com/package/ssh2

Frequently Asked Questions

What is CVE-2020-26301?
CVE-2020-26301 is a security vulnerability in Ssh2 involving OS Command Injection in ssh2 under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection').
Which Ssh2 versions are affected?
Affected versions include releases prior to 1.4.0 across affected packages: ssh2.
What version fixes CVE-2020-26301?
Upgrading to 1.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ssh2 affected?
Yes, ssh2 is affected in releases prior to 1.4.0. Upgrade your dependency to 1.4.0 or later.
What is the CVSS score of CVE-2020-26301?
CVE-2020-26301 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N.
What CWE is associated with CVE-2020-26301?
CVE-2020-26301 is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.).
How can I check npm dependencies for CVE-2020-26301?
Run the dependency tree command: 'npm ls ssh2'. 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-652h-xwhf-q4h6",
  "modified" : "2024-02-12T15:03:29Z",
  "published" : "2021-09-21T16:50:46Z",
  "aliases" : [ "CVE-2020-26301" ],
  "summary" : "OS Command Injection in ssh2",
  "details" : "ssh2 is client and server modules written in pure JavaScript for node.js. In ssh2 before version 1.4.0 there is a command injection vulnerability. The issue only exists on Windows. This issue may lead to remote code execution if a client of the library calls the vulnerable method with untrusted input. This is fixed in version 1.4.0.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "ssh2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-26301"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mscdex/ssh2/commit/f763271f41320e71d5cbee02ea5bc6a2ded3ca21"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mscdex/ssh2"
  }, {
    "type" : "ADVISORY",
    "url" : "https://securitylab.github.com/advisories/GHSL-2020-123-mscdex-ssh2"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/package/ssh2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-09-21T14:50:54Z",
    "nvd_published_at" : "2021-09-20T20:15:00Z"
  }
}