CVE-2024-39950 Overview
A critical vulnerability has been discovered in multiple Dahua Network Video Recorder (NVR) and IP Camera products. Attackers can send carefully crafted data packets to vulnerable interfaces to initiate unauthorized device initialization, potentially resetting the device to factory defaults and disrupting surveillance operations.
Critical Impact
This vulnerability allows remote, unauthenticated attackers to forcibly initialize Dahua NVR and IP camera devices over the network, resulting in complete loss of device configuration, recorded footage, and security settings.
Affected Products
- Dahua NVR4xxx-4KS2/L Series (4, 8, 16, 32-channel models)
- Dahua NVR4xxx-4KS2/I Series (16, 32, 64-channel models)
- Dahua NVR4xxx-4KS3 Series (4, 8, 16, 32-channel models)
- Dahua IPC-HFS8849G-Z3-LED and IPC-HFS8449G-Z7-LED IP Cameras
Discovery Timeline
- July 31, 2024 - CVE-2024-39950 published to NVD
- September 30, 2025 - Last updated in NVD database
Technical Details for CVE-2024-39950
Vulnerability Analysis
This vulnerability affects the device initialization interface in Dahua's embedded firmware. The flaw allows attackers to bypass normal authentication and authorization controls by sending specially crafted network packets to the vulnerable interface. When exploited, the device is forced into an initialization state, effectively performing a factory reset without proper authorization.
The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow) and CWE-20 (Improper Input Validation), indicating that the underlying issue involves improper handling of input data that can overflow stack buffers or bypass validation checks in the initialization routine.
Root Cause
The root cause of this vulnerability lies in inadequate input validation within the device initialization interface. The affected firmware fails to properly authenticate and validate incoming requests to the initialization endpoint, allowing unauthenticated users to trigger the device reset functionality. Additionally, the stack-based buffer overflow component (CWE-121) suggests that malformed packets can corrupt memory structures controlling the initialization process.
Attack Vector
The attack can be executed remotely over the network without requiring any authentication or user interaction. An attacker with network access to the vulnerable device can:
- Identify vulnerable Dahua NVR or IP camera devices on the network
- Craft malicious packets targeting the initialization interface
- Send the crafted packets to the device
- Trigger unauthorized device initialization, resetting all configurations
The device initialization results in loss of all recorded footage, user accounts, network configurations, and security settings, effectively rendering the surveillance system non-functional until reconfigured.
Detection Methods for CVE-2024-39950
Indicators of Compromise
- Unexpected device reboots or initialization events in NVR/IP camera logs
- Loss of device configuration or return to factory default settings
- Sudden disconnection of cameras from NVR systems
- Authentication failures as user credentials are reset
- Network traffic containing anomalous packets directed at device management ports
Detection Strategies
- Monitor network traffic for unusual connection patterns to Dahua device management interfaces
- Implement IDS/IPS rules to detect malformed packets targeting known Dahua device ports
- Configure SIEM alerts for device initialization events outside of maintenance windows
- Enable and review device audit logs for unauthorized configuration changes
Monitoring Recommendations
- Deploy network segmentation to isolate surveillance devices from untrusted network segments
- Implement continuous monitoring of device availability and configuration states
- Use SentinelOne Singularity for IoT to monitor embedded device behavior and detect anomalies
- Configure automated alerts when devices unexpectedly return to factory default states
How to Mitigate CVE-2024-39950
Immediate Actions Required
- Isolate affected Dahua NVR and IP camera devices from untrusted networks immediately
- Implement firewall rules to restrict access to device management interfaces to authorized management hosts only
- Review device logs for any evidence of exploitation or unauthorized initialization
- Apply firmware updates from Dahua as soon as available
- Backup current device configurations to enable rapid recovery if exploitation occurs
Patch Information
Dahua has released security guidance addressing this vulnerability. Organizations should consult the Dahua Security Advisory #768 for specific firmware versions that remediate this issue. Contact Dahua support or authorized distributors to obtain patched firmware for affected devices.
Workarounds
- Place all affected devices behind a properly configured firewall that blocks external access to management interfaces
- Enable VPN-only access for remote device management
- Implement network segmentation to isolate surveillance infrastructure from general network traffic
- Disable any unnecessary network services on affected devices
- Consider implementing a dedicated management VLAN for surveillance equipment
# Example firewall rule to restrict access to Dahua device management
# Allow only trusted management hosts (adjust IP ranges as needed)
iptables -A INPUT -p tcp --dport 37777 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 37777 -j DROP
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
