CVE-2025-10267: NUP Portal Authentication Bypass Flaw

CVE-2025-10267 Overview

CVE-2025-10267 affects the NUP Portal developed by NewType Infortech. The vulnerability stems from a missing authentication check [CWE-306] on a file upload endpoint. Unauthenticated remote attackers can send file upload requests directly to the server without credentials. If an attacker bypasses the file extension restrictions, they can upload a webshell and execute arbitrary code on the server. The issue was disclosed through TWCert, Taiwan's national CERT coordination center.

Critical Impact
Unauthenticated attackers can upload arbitrary files remotely, and bypassing extension filters enables webshell deployment and server-side code execution.

Affected Products

NUP Portal by NewType Infortech
Specific versions were not enumerated in the NVD record
Refer to the TWCert advisory for vendor-confirmed affected releases

Discovery Timeline

2025-09-12 - CVE-2025-10267 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-10267

Vulnerability Analysis

The NUP Portal exposes a file upload endpoint that does not enforce authentication before processing incoming requests. Any remote client with network reachability to the portal can invoke the upload handler. The application relies solely on file extension filtering as a security control. Extension-based allow/deny lists are known to be bypassable through techniques such as double extensions, case manipulation, null byte injection, or MIME type spoofing. When an attacker successfully places a server-executable file (such as .asp, .aspx, .jsp, or .php) within a web-accessible directory, the server will execute the file when it is requested. This chain converts a missing-authentication defect into remote code execution under the privileges of the web application process.

Root Cause

The root cause is Missing Authentication for a Critical Function [CWE-306]. The upload handler does not validate a session token, API key, or any authentication material before accepting a file. The secondary weakness is the reliance on client-controllable file extension checks instead of content inspection and safe storage locations.

Attack Vector

Exploitation requires only network access to the NUP Portal. The attacker crafts an HTTP POST request to the vulnerable upload endpoint with a payload file whose extension evades the filter. Once the file is written to a web-accessible path, the attacker requests the file URL to trigger execution. No user interaction and no prior privileges are required.

No verified public exploit code has been observed for CVE-2025-10267. See the TWCert Security Advisory for vendor-coordinated details.

Detection Methods for CVE-2025-10267

Indicators of Compromise

Unexpected files with server-executable extensions (.aspx, .jsp, .php, .asp) in NUP Portal upload directories
HTTP POST requests to portal upload endpoints from unauthenticated sessions or unusual source IPs
Web server access logs showing GET requests to newly created files immediately after upload activity
Outbound connections from the NUP Portal host to unfamiliar command-and-control infrastructure

Detection Strategies

Inspect web server and application logs for upload requests lacking authentication headers or session cookies
Baseline the contents of upload directories and alert on new files with executable extensions
Deploy web application firewall (WAF) rules to flag multipart uploads containing double extensions or script content

Monitoring Recommendations

Forward NUP Portal web server logs to a centralized SIEM for correlation with authentication events
Monitor process creation on the web server host for shells (cmd.exe, powershell.exe, /bin/sh) spawned by the web application user
Track file integrity in web-accessible directories using host-based integrity monitoring

How to Mitigate CVE-2025-10267

Immediate Actions Required

Restrict network access to the NUP Portal upload endpoint using firewall or reverse proxy allow lists
Contact NewType Infortech to obtain the vendor-supplied fix referenced in the TWCert advisory
Audit upload directories for unauthorized files and remove any suspicious artifacts
Rotate credentials and secrets accessible from the NUP Portal host if compromise is suspected

Patch Information

NewType Infortech has coordinated disclosure through TWCert. Administrators should consult the TWCert Security Advisory and the TWCert Security Alert for the fixed version and upgrade instructions. Apply the vendor patch to all NUP Portal instances.

Workarounds

Place the NUP Portal behind an authenticating reverse proxy that enforces identity before requests reach the application
Configure the web server to disable script execution in upload directories (for example, remove handler mappings for .aspx, .jsp, .php)
Enforce content-type validation and file magic-byte inspection in an upstream WAF until the patch is applied
Store uploaded files outside the web root and serve them through a controlled download handler

bash

# Example: disable script execution in an IIS upload directory via web.config
# Place this web.config inside the uploads folder
<configuration>
  <system.webServer>
    <handlers accessPolicy="Read" />
    <staticContent>
      <clientCache cacheControlMode="DisableCache" />
    </staticContent>
  </system.webServer>
</configuration>