How CVE-2025-30401 Works
CVE-2025-30401 is a critical spoofing vulnerability in WhatsApp for Windows (prior to v2.2450.6). The flaw occurs due to improper handling of file attachments—WhatsApp validates files based on MIME type but relies on the file extension to determine the opening handler. An attacker can craft a malicious file with a mismatched extension (e.g., a `.exe` disguised as .jpg) to bypass security checks. When the victim manually opens the attachment, the system executes it using the handler associated with the extension, leading to arbitrary code execution. This exploit requires user interaction but poses high risk due to WhatsApp’s widespread use.
DailyCVE Form:
Platform: WhatsApp (Windows)
Version: <2.2450.6
Vulnerability: Spoofing → RCE
Severity: Critical
Date: 04/08/2025
What Undercode Say:
Exploitation:
- Craft a malicious file with conflicting MIME type and extension (e.g., `malware.exe` renamed to
invoice.pdf).
2. Send via WhatsApp to the target.
- Trigger execution when the victim manually opens the file.
Proof-of-Concept (PoC) Command:
Generate a decoy PDF with embedded payload
$payload = [bash]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes("malicious code"));
echo "%%PDF-1.4" > fake.pdf.exe
Protection:
1. Update WhatsApp to v2.2450.6 or later.
2. Disable automatic file handlers in Windows:
Windows Registry Editor Version 5.00 [HKEY_CLASSES_ROOT\exefile\shell\open\command] @=""\"%1\" %""
3. Educate users to verify file extensions before opening.
Detection:
Scan for mismatched MIME/extensions in attachments:
import magic
file_mime = magic.from_file("file.exe", mime=True)
if not file_mime == "application/pdf":
print("Suspicious file detected!")
Mitigation:
- Network filtering: Block executable attachments at the gateway.
- Endpoint protection: Deploy EDR solutions to monitor process injection.
- Sandboxing: Open WhatsApp attachments in isolated environments.
Criticality: 9.5 CVSS (CVSS:4.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H)
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-30401
Extra Source Hub:
Undercode
