webcrack has an Arbitrary File Write Vulnerability on Windows when Parsing and Saving a Malicious Bundle

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.2 · CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:H/SA:L · score source

EPSS

• CVE-2024-43373: 0.45% estimated exploitation activity in the next 30 days; percentile 38.97 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary An arbitrary file write vulnerability exists in the webcrack module when processing specifically crafted malicious code on Windows systems. This vulnerability is triggered when using the unpack bundles feature in conjunction with the saving feature. If a module name includes a path traversal sequence with Windows path separators, an attacker can exploit this to overwrite files on the host system. Details Source: packages/webcrack/src/unpack/bundle.ts#L79 In this code, the application explicitly relies on the POSIX version of path utilities (dirname, join, normalize) from Node.js. However, the vulnerability arises because the POSIX version of the normalize function does not recognize \ as a path separator. As a result, on Windows systems, the path traversal check fails, allowing an attacker to write files to unintended locations. PoC The following proof of concept demonstrates how this vulnerability can be exploited to overwrite and hijack the debug module in Node.js:…

Published by the source

14 Aug 2024, 18:01 UTC

Last modified by the source

18 Nov 2024, 16:27 UTC

Source last checked

26 Oct 2026, 12:31 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-ccqh-278p-xq6w

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-ccqh-278p-xq6w

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# Patch Next advisory brief: CVE-2024-43373

Advisory: webcrack has an Arbitrary File Write Vulnerability on Windows when Parsing and Saving a Malicious Bundle
IDs: CVE-2024-43373, GHSA-ccqh-278p-xq6w
Record: https://patchnext.com/advisories/cve-2024-43373 (revision 3, source checked 26 Oct 2026, 12:31 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: webcrack 2.14.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm webcrack: affected <= 2.14.0; fixed in 2.14.1

## Suggested inspection (read-only)
- `npm ls webcrack --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on webcrack.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-ccqh-278p-xq6w (OSV record GHSA-ccqh-278p-xq6w lists affected ranges: npm webcrack >=0 <2.14.1 (fixed))
- Verified: https://github.com/advisories/GHSA-ccqh-278p-xq6w (GitHub-reviewed advisory GHSA-ccqh-278p-xq6w lists affected ranges: npm webcrack >=0 <=2.14.0)

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