Ecosyste.ms: Advisories

Security Advisories: MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWYycnAtMzh2Zy1qM2do

Null characters not escaped

Impact

Anyone using Shescape to defend against shell injection may still be vulnerable against shell injection if the attacker manages to insert a null character into the payload. For example (on Windows):

const cp = require("child_process");
const shescape = require("shescape");

const nullChar = String.fromCharCode(0);
const payload = "foo\" && ls -al ${nullChar} && echo \"bar";
console.log(cp.execSync(`echo ${shescape.quote(payload)}`));
// foototal 3
// drwxr-xr-x 1 owner XXXXXX      0 Mar 13 18:44 .
// drwxr-xr-x 1 owner XXXXXX      0 Mar 13 00:09 ..
// drwxr-xr-x 1 owner XXXXXX      0 Mar 13 18:42 folder                                                                 
// -rw-r--r-- 1 owner XXXXXX      0 Mar 13 18:42 file

Patches

The problem has been patched in v1.1.3 which you can upgrade to now. No further changes are required.

Workarounds

Alternatively, null characters can be stripped out manually using e.g. arg.replace(/\u{0}/gu, "")

Permalink: https://github.com/advisories/GHSA-f2rp-38vg-j3gh
JSON: https://advisories.ecosyste.ms/api/v1/advisories/MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLWYycnAtMzh2Zy1qM2do
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: almost 4 years ago
Updated: about 2 years ago

CVSS Score: 6.3
CVSS vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:N

EPSS Percentage: 0.00081
EPSS Percentile: 0.36501

Identifiers: GHSA-f2rp-38vg-j3gh, CVE-2021-21384
References:

• https://github.com/ericcornelissen/shescape/security/advisories/GHSA-f2rp-38vg-j3gh
• https://github.com/ericcornelissen/shescape/commit/07a069a66423809cbedd61d980c11ca44a29ea2b
• https://github.com/ericcornelissen/shescape/releases/tag/v1.1.3
• https://nvd.nist.gov/vuln/detail/CVE-2021-21384
• https://www.npmjs.com/package/shescape
• https://github.com/advisories/GHSA-f2rp-38vg-j3gh

Repository: https://github.com/ericcornelissen/shescape
Blast Radius: 9.1

Affected Packages