CVE-2025-29660: Yiiot XY-3820 Path Traversal Vulnerability

CVE-2025-29660 Overview

A critical directory traversal vulnerability exists in the daemon process of the Yi IOT XY-3820 IP camera firmware version 6.0.24.10. The device exposes a TCP service on port 6789 that lacks proper input validation, enabling attackers to execute arbitrary scripts present on the device by sending specially crafted TCP requests using directory traversal techniques. This vulnerability allows unauthenticated remote attackers to achieve complete device compromise over the network.

Critical Impact

Unauthenticated remote code execution via directory traversal on IoT camera devices, enabling complete device takeover with no user interaction required.

Affected Products

• Yi IOT XY-3820 Firmware version 6.0.24.10
• Yi IOT XY-3820 Hardware

Discovery Timeline

• April 21, 2025 - CVE-2025-29660 published to NVD
• June 23, 2025 - Last updated in NVD database

Technical Details for CVE-2025-29660

Vulnerability Analysis

The vulnerability resides in the daemon process of the Yi IOT XY-3820 IP camera, which exposes a TCP service listening on port 6789. This service processes incoming requests without implementing adequate input validation or sanitization, specifically failing to neutralize directory traversal sequences such as ../ in user-supplied input.

When the daemon receives a crafted TCP request containing path traversal characters, it fails to properly validate the requested resource path, allowing an attacker to escape the intended directory structure. This enables the execution of arbitrary scripts or binaries that exist elsewhere on the device's filesystem. The vulnerability is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory).

Root Cause

The root cause is improper input validation in the TCP service's request handler. The daemon process fails to sanitize directory traversal sequences (../, ..%2f, etc.) from incoming request paths before using them in file system operations. This allows attackers to break out of the intended directory and access or execute files from arbitrary locations on the device's filesystem.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker with network access to the vulnerable device can send specially crafted TCP packets to port 6789 containing directory traversal sequences. These sequences allow the attacker to reference and execute scripts or binaries located outside the intended service directory.

The attack leverages the exposed TCP service which was likely intended for device management or communication purposes but lacks proper security controls. By chaining directory traversal with script execution capabilities, an attacker can achieve remote code execution and gain full control of the compromised device.

For detailed technical analysis and proof-of-concept information, refer to the GitHub CVE-2025-29660 Research repository.

Detection Methods for CVE-2025-29660

Indicators of Compromise

• Unexpected network connections to port 6789 on Yi IOT XY-3820 devices from external or unauthorized IP addresses
• TCP packets containing directory traversal sequences (../, ..%2f, %2e%2e/) targeting port 6789
• Unusual process execution or script activity originating from the camera device
• Network traffic patterns indicating command and control communication from IoT devices

Detection Strategies

• Implement network intrusion detection rules to identify directory traversal patterns in TCP traffic destined for port 6789
• Monitor for anomalous outbound connections from IoT camera devices that may indicate post-exploitation activity
• Deploy network segmentation monitoring to detect unauthorized access attempts to IoT device management ports
• Use packet inspection to identify malformed or suspicious TCP requests targeting Yi IOT devices

Monitoring Recommendations

• Isolate IoT cameras on dedicated network segments with restricted access and egress filtering
• Implement continuous network traffic analysis for all IoT device communications
• Enable logging on network security devices to capture connection attempts to port 6789
• Deploy honeypots mimicking vulnerable IoT camera services to detect active exploitation attempts

How to Mitigate CVE-2025-29660

Immediate Actions Required

• Block external network access to port 6789 on all Yi IOT XY-3820 devices using firewall rules
• Segment IoT cameras onto isolated VLANs with restricted network access
• Audit network logs for any evidence of prior exploitation attempts targeting this vulnerability
• Consider temporarily disconnecting affected devices from the network until a patch is available

Patch Information

At the time of publication, no vendor patch has been confirmed for this vulnerability. Organizations should monitor the GitHub PoC Repository for updates and check with Yi IOT for firmware updates addressing this issue.

Workarounds

• Implement strict firewall rules blocking all inbound connections to port 6789 from untrusted networks
• Place affected devices behind a VPN or authenticated gateway to restrict network exposure
• Deploy network-level intrusion prevention systems (IPS) with rules to detect and block directory traversal attacks
• Consider replacing affected devices with alternatives that have active security support if no patch becomes available

# Example iptables rule to block external access to vulnerable service
iptables -A INPUT -p tcp --dport 6789 -s ! 192.168.1.0/24 -j DROP

# Example rule to log connection attempts for monitoring
iptables -A INPUT -p tcp --dport 6789 -j LOG --log-prefix "YiIOT-6789: "