CVE-2024-29949: Hikvision NVR RCE Vulnerability

CVE-2024-29949 Overview

CVE-2024-29949 is a command injection vulnerability (CWE-77) affecting certain Hikvision Network Video Recorder (NVR) devices. This security flaw enables an authenticated user with administrative privileges to execute arbitrary commands on the affected system. The vulnerability requires network access and administrative credentials to exploit, making it a post-authentication attack vector that could lead to complete device compromise.

Critical Impact

Authenticated administrators can execute arbitrary system commands, potentially leading to complete device takeover, data exfiltration, persistent backdoor installation, or lateral movement within surveillance networks.

Affected Products

• Hikvision NVR Devices (specific models detailed in vendor advisory)
• Network Video Recorder firmware versions prior to patched releases
• Hikvision surveillance infrastructure components

Discovery Timeline

• April 2, 2024 - CVE-2024-29949 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2024-29949

Vulnerability Analysis

This command injection vulnerability exists in certain Hikvision NVR devices, classified under CWE-77 (Improper Neutralization of Special Elements used in a Command). The flaw allows authenticated users with administrative rights to inject and execute arbitrary operating system commands on the underlying system.

Command injection vulnerabilities occur when user-supplied input is improperly sanitized before being passed to system shell commands or interpreters. In this case, the NVR device fails to adequately validate or sanitize input from administrative interfaces, allowing malicious command sequences to be executed with the privileges of the application or underlying service.

The network-accessible nature of NVR devices, combined with the post-authentication requirement, means attackers would need to first obtain valid administrative credentials through credential theft, brute-force attacks, default credential exploitation, or social engineering before exploiting this vulnerability.

Root Cause

The vulnerability stems from improper neutralization of special elements used in command construction (CWE-77). The affected Hikvision NVR firmware fails to properly sanitize or validate user input before incorporating it into system commands. This allows specially crafted input containing shell metacharacters or command separators to break out of the intended command context and execute additional arbitrary commands.

Attack Vector

The attack is network-based, requiring the attacker to have authenticated access to the NVR device with administrative privileges. The exploitation flow involves:

1. Attacker obtains valid administrative credentials for the target NVR device
2. Attacker authenticates to the NVR web interface or management API
3. Attacker identifies the vulnerable input parameter or function
4. Attacker crafts malicious input containing command injection payloads
5. The NVR processes the input without proper sanitization, executing the injected commands
6. Arbitrary commands execute with the privileges of the NVR service

The vulnerability does not require user interaction beyond the attacker's own actions, and the scope is unchanged, meaning the compromised component and impacted component are the same.

Detection Methods for CVE-2024-29949

Indicators of Compromise

• Unusual outbound network connections from NVR devices to unknown external IP addresses
• Unexpected processes or services running on NVR systems
• Anomalous administrative login patterns or authentication attempts
• Modified system files or configurations on NVR devices
• Suspicious command history entries or shell activity logs

Detection Strategies

• Monitor NVR administrative interface access logs for unusual activity patterns
• Implement network segmentation to isolate surveillance devices and detect anomalous cross-segment traffic
• Deploy intrusion detection systems (IDS) with signatures for command injection patterns
• Enable verbose logging on NVR devices and forward logs to centralized SIEM solutions
• Monitor for unexpected firmware modifications or configuration changes

Monitoring Recommendations

• Establish baseline behavior for NVR device network traffic and alert on deviations
• Implement real-time alerting for administrative login events from unusual source IPs
• Configure file integrity monitoring on critical NVR system files where supported
• Review authentication logs regularly for signs of credential abuse or brute-force attempts

How to Mitigate CVE-2024-29949

Immediate Actions Required

• Update affected Hikvision NVR devices to the latest firmware version as detailed in the vendor security advisory
• Audit administrative account credentials and enforce strong password policies
• Restrict network access to NVR management interfaces using firewall rules or VLANs
• Review and limit the number of accounts with administrative privileges
• Enable two-factor authentication for administrative access where available

Patch Information

Hikvision has released security updates to address this vulnerability. Administrators should consult the Hikvision Security Advisory for detailed patch information, affected model numbers, and updated firmware versions. It is critical to verify the firmware version after applying updates to confirm successful remediation.

Workarounds

• Implement network segmentation to isolate NVR devices from general corporate networks
• Restrict administrative interface access to trusted IP addresses only using access control lists
• Disable remote administrative access and require physical or local network access for management tasks
• Monitor administrative sessions and implement session timeout policies
• Consider deploying a web application firewall (WAF) in front of NVR management interfaces to filter malicious input

# Example network segmentation using firewall rules
# Restrict NVR management access to specific trusted IP ranges

# Allow management access only from trusted admin subnet
iptables -A INPUT -p tcp --dport 443 -s 192.168.100.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -s 192.168.100.0/24 -j ACCEPT

# Block all other management access
iptables -A INPUT -p tcp --dport 443 -j DROP
iptables -A INPUT -p tcp --dport 80 -j DROP