CVE-2024-42531 Overview
CVE-2024-42531 is an authentication bypass vulnerability affecting the Ezviz Internet PT Camera CS-CV246 (firmware version D15655150). This flaw allows an unauthenticated remote attacker to potentially access the camera's live video stream by crafting specific RTSP packets with targeted URLs that can be used to redirect the camera feed. The vulnerability stems from improper input validation (CWE-20) in the device's RTSP protocol handling.
It should be noted that the vendor disputes the severity of this vulnerability, claiming that while the proof-of-concept code can establish RTSP protocol communication, it cannot actually obtain video or audio data, and therefore poses no risk. However, the vulnerability has been assigned a critical severity rating in the NVD.
Critical Impact
This vulnerability could allow unauthorized remote access to live video feeds from affected Ezviz cameras, potentially compromising physical security monitoring and user privacy.
Affected Products
- Ezviz Internet PT Camera CS-CV246
- Firmware version D15655150
Discovery Timeline
- 2024-08-23 - CVE-2024-42531 published to NVD
- 2024-08-29 - Last updated in NVD database
Technical Details for CVE-2024-42531
Vulnerability Analysis
This vulnerability exists in the RTSP (Real Time Streaming Protocol) handling component of the Ezviz CS-CV246 camera. RTSP is commonly used for establishing and controlling media sessions between endpoints, particularly for streaming video content from IP cameras.
The core issue involves improper input validation when processing RTSP packets containing specially crafted URLs. An unauthenticated attacker on the network can send malformed RTSP requests to the camera that bypass normal authentication mechanisms, potentially allowing access to the video stream without proper credentials.
The network-accessible nature of this vulnerability means that any device capable of reaching the camera over the network could potentially exploit this flaw without requiring any user interaction or prior authentication.
Root Cause
The root cause is classified as CWE-20: Improper Input Validation. The camera's RTSP packet handler fails to properly validate and sanitize incoming URL parameters within RTSP requests. This allows attackers to craft malicious packets that the device processes without enforcing proper authentication checks.
The firmware does not adequately verify that RTSP session requests originate from authenticated sources before processing URL redirection parameters, creating an authentication bypass scenario.
Attack Vector
The attack is conducted over the network targeting the camera's RTSP service. An attacker would:
- Identify an Ezviz CS-CV246 camera on the target network
- Craft RTSP packets containing specific URL patterns designed to bypass authentication
- Send these packets to the camera's RTSP service port (typically TCP 554)
- Potentially redirect or access the camera's video feed without authentication
The vulnerability mechanism involves crafting specific RTSP packet sequences with targeted URLs. A proof-of-concept demonstrating the RTSP communication establishment has been published to the GitHub Repository by Anonymous120386. Technical details about the specific packet construction can be found in that repository.
Detection Methods for CVE-2024-42531
Indicators of Compromise
- Unusual or unauthorized RTSP connections to cameras on port 554
- Multiple failed or suspicious RTSP session establishment attempts from unknown IP addresses
- Network traffic patterns showing RTSP communication with cameras from non-standard management hosts
- Logs indicating RTSP sessions established without corresponding authenticated user activity
Detection Strategies
- Monitor network traffic for anomalous RTSP protocol activity targeting camera devices
- Implement network segmentation to isolate IoT cameras and monitor inter-segment traffic
- Deploy intrusion detection signatures for suspicious RTSP packet patterns
- Audit RTSP connection logs on camera management platforms for unauthorized access attempts
Monitoring Recommendations
- Enable logging on network firewalls and IDS/IPS for RTSP traffic (TCP/UDP 554)
- Implement behavioral analytics to detect unusual camera access patterns
- Monitor for reconnaissance activity targeting RTSP-enabled devices on the network
- Configure alerts for RTSP connections originating from untrusted network segments
How to Mitigate CVE-2024-42531
Immediate Actions Required
- Isolate affected Ezviz CS-CV246 cameras on a dedicated network segment with strict access controls
- Block external network access to camera RTSP ports (TCP 554) at the firewall level
- Implement network ACLs to restrict RTSP communication to authorized management hosts only
- Review camera access logs for any signs of unauthorized access or exploitation attempts
Patch Information
As of the last modification date (2024-08-29), no official vendor patch has been referenced in the CVE data. The vendor (Ezviz) has disputed the vulnerability's impact, stating their position is that the proof-of-concept cannot obtain actual video or audio data. Users should monitor the Ezviz Homepage for any firmware updates or security advisories addressing this issue.
Organizations should contact Ezviz support directly for guidance on firmware updates and the vendor's official position on this vulnerability.
Workarounds
- Segment camera networks from general enterprise networks using VLANs and firewalls
- Restrict RTSP port access (TCP 554) to only authorized monitoring systems via firewall rules
- Disable RTSP if not required and use alternative secure streaming methods where available
- Implement VPN or other authenticated tunnels for any remote camera access requirements
- Consider replacing affected devices with models that have confirmed security patches
# Example firewall rule to restrict RTSP access (iptables)
# Allow RTSP only from trusted management subnet
iptables -A INPUT -p tcp --dport 554 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 554 -j DROP
# Example VLAN isolation for camera network
# Configure on network switch to isolate cameras
# VLAN 100 = Camera network, VLAN 1 = Management
# Ensure inter-VLAN routing restricts traffic appropriately
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
