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CVE-2025-24985 — Windows Fast FAT File System Driver Zero-Day Remote Code Execution

Key facts

CVE-2025-24985 is a Critical (9.8) vulnerability: Windows Fast FAT File System Driver Zero-Day Remote Code Execution. This entry ships a detection-only PoC. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2025-03-11), confirming active exploitation in the wild.

Actively exploited — on the CISA KEV catalog

CVE-2025-24985 is listed on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2025-03-11), confirming exploitation in the wild. Federal remediation deadline: 2025-04-01. Prioritise patching and deploy the detection and prevention rules below.
CVE CVE-2025-24985
Severity Critical (9.8)
CISA KEV Actively exploited (added 2025-03-11)
Detection / prevention —
PoC poc.py
Source 2025/CVE-2025-24985/

Details

CVSS Type

Overview

Attribute Value
CVE ID CVE-2025-24985
Severity Critical
CVSS Score 9.8
Affected Product Windows Fast FAT File System Driver
Vulnerability Type Zero-Day Remote Code Execution
CWE CWE-787

Description

Zero-day vulnerability in Windows Fast FAT File System Driver that was actively exploited in the wild before Microsoft released a patch. Affects a vast number of Windows systems.

Affected Versions

  • Windows 10, Windows 11, Windows Server

Verification Process

The PoC uses a multi-stage verification approach:

Step 1: Product/Version Detection (Passive)

[*] Query target endpoint
[*] Detect product signatures and extract version
[*] Check if version is in vulnerable range

Step 2: Active Vulnerability Testing

Method Description Detection
Error-based Inject payloads that trigger error messages Error indicators in response
Timing-based Inject delay commands and measure response Response time > baseline + delay
Response-based Check for expected patterns in response Pattern match in response body
Callback-based Trigger OOB request to attacker server HTTP request received

Verification Flow

┌─────────────────────────────────────────────────────────────┐
│                    Product Detection                         │
│  Query target → Detect product/version                      │
│  Check if version in vulnerable range                       │
└─────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────┐
│               Active Vulnerability Testing                   │
│                                                              │
│  1. Error-based Test                                         │
│     └─ Send payload → Check for error indicators            │
│     └─ If error found → CONFIRMED VULNERABLE                │
│                                                              │
│  2. Timing-based Test                                        │
│     └─ Send delay payload → Measure response time           │
│     └─ If delayed → CONFIRMED VULNERABLE                    │
│                                                              │
│  3. Callback-based Test (if URL provided)                    │
│     └─ Send OOB payload → Check callback server             │
│     └─ If request received → CONFIRMED VULNERABLE           │
└─────────────────────────────────────────────────────────────┘

Usage

# Full vulnerability check (version + active testing)
python3 poc.py -t https://target.com -c

# Version-only check (passive, no payloads sent)
python3 poc.py -t https://target.com -c --version-only

# With OOB callback (most reliable)
python3 poc.py -t https://target.com -c --callback http://your-server.com

Mitigation

  1. Upgrade to the latest patched version
  2. Apply workarounds if patch unavailable
  3. Monitor for exploitation attempts
  4. Network segmentation to limit exposure

References

Frequently asked questions

What is CVE-2025-24985?

CVE-2025-24985 is a Critical (9.8) vulnerability: Windows Fast FAT File System Driver Zero-Day Remote Code Execution. This entry ships a detection-only PoC. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2025-03-11), confirming active exploitation in the wild.

How do I detect CVE-2025-24985?

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2025-24985?

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

Is CVE-2025-24985 actively exploited?

Yes. CVE-2025-24985 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2025-03-11, which means it has been exploited in the wild. CISA set a federal remediation deadline of 2025-04-01. Prioritise patching and deploy the detection and prevention rules above.

For authorized security testing and research only. See the full source and NVD record.