CVE-2022-29499: Mitel MiVoice Connect RCE Vulnerability

CVE-2022-29499 Overview

CVE-2022-29499 is a critical remote code execution vulnerability affecting the Service Appliance component in Mitel MiVoice Connect through version 19.2 SP3. The vulnerability arises from incorrect data validation, enabling remote attackers to execute arbitrary code on affected systems without authentication. This vulnerability has been actively exploited in the wild and is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog.

Critical Impact

This vulnerability allows unauthenticated remote attackers to achieve complete system compromise through remote code execution on Mitel MiVoice Connect Service Appliances, including SA 100, SA 400, and Virtual SA devices.

Affected Products

• Mitel MiVoice Connect through version 19.2 SP3
• Mitel Service Appliance SA 100
• Mitel Service Appliance SA 400
• Mitel Virtual SA

Discovery Timeline

• 2022-04-26 - CVE-2022-29499 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2022-29499

Vulnerability Analysis

The vulnerability exists in the Service Appliance component of Mitel MiVoice Connect, a unified communications platform widely deployed in enterprise environments. The core issue stems from improper input validation (CWE-20) in how the Service Appliance processes incoming data.

Due to incorrect data validation mechanisms, the application fails to properly sanitize user-supplied input before processing it in a security-sensitive context. This allows attackers to craft malicious requests that bypass intended security controls and achieve code execution on the underlying system.

The network-accessible nature of this vulnerability, combined with no authentication requirements and no user interaction needed, makes it particularly dangerous for organizations running affected Mitel deployments. Successful exploitation grants attackers full control over the compromised appliance, potentially allowing lateral movement within the network.

Root Cause

The root cause of CVE-2022-29499 is improper input validation (CWE-20) in the Service Appliance component. The application fails to adequately validate and sanitize data received from external sources before using it in operations that can affect system state or execute commands. This fundamental input validation failure allows attackers to inject and execute arbitrary code on the target system.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or user interaction. An attacker can remotely target the Service Appliance component by sending specially crafted requests that exploit the data validation flaw. The attack does not require any privileges on the target system, making it accessible to any attacker who can reach the vulnerable service over the network.

The exploitation process involves sending malformed or malicious input to the Service Appliance that bypasses the inadequate validation checks. When the component processes this input, it inadvertently executes attacker-controlled code with the privileges of the service, leading to complete system compromise.

Detection Methods for CVE-2022-29499

Indicators of Compromise

• Unexpected outbound network connections from Mitel MiVoice Connect Service Appliances
• Anomalous process execution originating from the Service Appliance component
• Unusual system calls or shell spawning from MiVoice Connect services
• Evidence of unauthorized access or modifications to Service Appliance configurations

Detection Strategies

• Monitor network traffic to and from Mitel MiVoice Connect appliances for suspicious patterns or anomalous requests
• Implement intrusion detection system (IDS) rules to detect exploitation attempts targeting the Service Appliance component
• Review authentication and access logs for the Service Appliance for signs of unauthorized activity
• Deploy endpoint detection and response (EDR) solutions on systems hosting Mitel services to identify post-exploitation activity

Monitoring Recommendations

• Enable comprehensive logging on all Mitel MiVoice Connect Service Appliances
• Implement network segmentation to isolate MiVoice Connect infrastructure from critical systems
• Configure alerts for any anomalous behavior on SA 100, SA 400, and Virtual SA devices
• Regularly audit Service Appliance configurations and compare against known-good baselines

How to Mitigate CVE-2022-29499

Immediate Actions Required

• Apply the security patches provided by Mitel immediately to all affected Service Appliances
• If patching is not immediately possible, restrict network access to the Service Appliance component using firewall rules
• Conduct a forensic review of affected systems to identify any signs of prior compromise
• Review and restrict which systems and users can access Mitel MiVoice Connect administrative interfaces

Patch Information

Mitel has released security patches to address this vulnerability. Organizations should refer to Mitel Security Advisory 22-0002 for detailed patch information and update instructions. Given this vulnerability is actively exploited and listed in the CISA Known Exploited Vulnerabilities Catalog, immediate patching is strongly recommended.

Workarounds

• Implement strict network access controls to limit exposure of Service Appliance interfaces to trusted networks only
• Place Mitel MiVoice Connect appliances behind a firewall or VPN that requires authentication
• Disable or restrict unnecessary services on the Service Appliance to reduce the attack surface
• Monitor for and block suspicious traffic patterns associated with exploitation attempts

# Example firewall rule to restrict access to Mitel Service Appliance
# Adjust IP ranges according to your environment
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP