HOMEVULNERABILITIESCVE-2021-4279
CRITICAL

CVE-2021-4279

CWE-1321Published: December 25, 2022· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official 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.

NVD Source

Risk Analysis

The Starcounter-Jack JSON-Patch library is affected by a prototype pollution vulnerability. This critical flaw allows remote attackers to modify object attributes, potentially leading to system compromise.

While the exploit has been disclosed to the public, it is not currently in the KEV catalog. It is remotely exploitable.

Recommended Action

Upgrade the json-patch component to version 3.1.1 or later.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-4279 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

starcounter-jack1 product(s)
json-patch
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (10)

Quick Facts

CVE IDCVE-2021-4279
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-1321
CISA KEVNo
Affected1 vendor(s)
PublishedDec 25, 2022

Related CVEs (CWE-1321)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-4279 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.