CVE-2026-67608: Telenia TVox OS Command Injection Flaw

CVE-2026-67608 Overview

CVE-2026-67608 is an OS command injection vulnerability in Telenia Software TVox affecting version 26.5.3 and prior 26.x releases, along with version 24.9.21 and prior 24.x releases. The flaw resides in action_audio.php, where the pid request parameter is passed directly into an exec() call when the action parameter equals checkProcess. Authenticated attackers can inject arbitrary operating system commands that execute with the privileges of the apache user. The issue is classified under CWE-78 (Improper Neutralization of Special Elements used in an OS Command).

Critical Impact

Authenticated attackers can achieve arbitrary command execution as the apache user on affected TVox instances, enabling lateral movement and full compromise of the hosting server.

Affected Products

• Telenia Software TVox versions 26.x through 26.5.3
• Telenia Software TVox versions 24.x through 24.9.21
• Deployments exposing action_audio.php to authenticated users

Discovery Timeline

• 2026-08-03 - CVE-2026-67608 published to NVD
• 2026-08-03 - Last updated in NVD database

Technical Details for CVE-2026-67608

Vulnerability Analysis

The vulnerability lives in the action_audio.php endpoint of TVox. When the action query parameter is set to checkProcess, the handler passes the value of the pid parameter into a PHP exec() call without sanitization or validation. Attackers who possess valid credentials can append shell metacharacters to the pid value to break out of the intended command and execute arbitrary payloads. Successful exploitation grants command execution under the apache service account, which typically holds access to web application files, configuration secrets, and internal network resources.

Root Cause

The root cause is missing input neutralization on user-supplied data before it reaches an operating system command interpreter. The pid parameter is expected to be a numeric process identifier but is concatenated into a shell command string. No allow-list validation, type coercion, or argument escaping is applied prior to invocation of exec(), matching the [CWE-78] pattern for OS command injection.

Attack Vector

Exploitation occurs over the network against the TVox web interface. The attacker must first authenticate to the application, then issue an HTTP request to action_audio.php with action=checkProcess and a crafted pid value containing shell metacharacters such as ;, |, or backticks. The injected commands run in the context of the Apache worker process. See the VulnCheck Telenia TVOX Advisory and the Karma In Security Advisory KIS-2026-15 for further technical detail.

No verified public exploit code is available. The vulnerability mechanism is described in prose per the referenced advisories.

Detection Methods for CVE-2026-67608

Indicators of Compromise

• HTTP requests to action_audio.php containing action=checkProcess and shell metacharacters (;, |, &, $(, backticks) in the pid parameter
• Child processes spawned by the apache user that are not legitimate audio-processing binaries, such as sh, bash, curl, wget, nc, or python
• Outbound network connections initiated by Apache worker processes to unfamiliar hosts
• New or modified files under the TVox web root or /tmp created by the apache account

Detection Strategies

• Inspect web server access logs for action_audio.php requests where the pid parameter contains non-numeric characters
• Correlate web request events with process-creation telemetry to flag Apache-spawned shells
• Alert on any interactive shell or scripting interpreter whose parent is httpd or apache2
• Baseline legitimate TVox process activity and treat deviations as high-priority events

Monitoring Recommendations

• Forward Apache access and error logs, along with Linux process telemetry, to a centralized analytics platform for correlation
• Enable auditd rules covering execve calls under the apache UID to capture command-line arguments
• Monitor egress traffic from TVox hosts for connections to unexpected external destinations
• Track authentication events against the TVox application to identify credential abuse preceding exploitation

How to Mitigate CVE-2026-67608

Immediate Actions Required

• Upgrade TVox to a fixed release beyond 26.5.3 for the 26.x branch and beyond 24.9.21 for the 24.x branch as published by Telenia Software
• Restrict network access to the TVox management interface to trusted administrative networks or VPN clients
• Rotate credentials for all TVox users, especially any accounts with broad application access
• Review Apache and system logs for prior exploitation attempts against action_audio.php

Patch Information

Refer to the Telenia Software Homepage and the VulnCheck Telenia TVOX Advisory for vendor-supplied fixed versions and patch guidance. Apply the vendor update to all TVox 26.x and 24.x deployments.

Workarounds

• Block or restrict access to action_audio.php at a reverse proxy or web application firewall when the action parameter equals checkProcess
• Enforce strict server-side validation that rejects any pid value containing non-digit characters
• Reduce the privileges available to the apache runtime user by tightening filesystem permissions and disabling unnecessary shell utilities
• Require multi-factor authentication for TVox accounts to raise the barrier for the required authenticated access

# Example WAF rule concept: drop requests where pid is non-numeric on the checkProcess action
# ModSecurity-style pseudo-rule
SecRule REQUEST_URI "@contains action_audio.php" \
    "chain,phase:2,deny,status:400,id:1026067608,msg:'CVE-2026-67608 TVox command injection attempt'"
    SecRule ARGS:action "@streq checkProcess" "chain"
    SecRule ARGS:pid "!@rx ^[0-9]+$"