CVE-2021-36260: Hikvision Camera Firmware RCE Vulnerability

CVE-2021-36260 Overview

CVE-2021-36260 is a command injection vulnerability affecting the web server component of numerous Hikvision surveillance products, including IP cameras, PTZ cameras, thermal cameras, and network video recorders (NVRs). The vulnerability stems from insufficient input validation in the device's web interface, allowing remote attackers to exploit the flaw by sending specially crafted HTTP messages containing malicious commands. Successful exploitation enables unauthenticated remote code execution with root privileges on the affected device.

This vulnerability has gained significant attention due to the widespread deployment of Hikvision cameras globally and has been actively exploited in the wild. CISA has added CVE-2021-36260 to its Known Exploited Vulnerabilities (KEV) catalog, underscoring the real-world threat posed by this security flaw.

Critical Impact

This vulnerability allows unauthenticated remote attackers to execute arbitrary commands with root privileges on vulnerable Hikvision devices via the network, potentially enabling full device compromise, surveillance feed interception, lateral movement, and botnet recruitment.

Affected Products

• Hikvision DS-2CD Series IP Cameras (multiple models including DS-2CD2026G2, DS-2CD2046G2, DS-2CD2066G2, DS-2CD2086G2, and many others)
• Hikvision PTZ Cameras (PTZ-N2204I-DE3, PTZ-N4215-DE3, PTZ-N5225I-A, DS-2DF series)
• Hikvision DS-7xxx Series Network Video Recorders (DS-7604NI, DS-7608NI, DS-7616NI, DS-7104NI, DS-7108NI)
• Hikvision Thermal Cameras (DS-2TD series)
• Hikvision Explosion-Proof Cameras (DS-2XE series)

Discovery Timeline

• September 22, 2021 - CVE-2021-36260 published to NVD
• November 10, 2025 - Last updated in NVD database

Technical Details for CVE-2021-36260

Vulnerability Analysis

CVE-2021-36260 is a command injection vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command) present in the embedded web server of affected Hikvision products. The vulnerability exists because the web server fails to properly validate and sanitize user-supplied input before passing it to system shell commands.

The attack can be launched remotely over the network without requiring any authentication credentials or user interaction. An attacker with network access to a vulnerable device can achieve complete system compromise by injecting operating system commands through the web interface. Since these devices typically run with root privileges, successful exploitation grants the attacker full administrative control over the camera or NVR.

The impact of this vulnerability is severe: attackers can access video feeds, disable recording functionality, modify device configurations, pivot to other network resources, or incorporate compromised devices into botnets for distributed denial-of-service attacks or cryptomining operations.

Root Cause

The root cause of CVE-2021-36260 lies in the web server's failure to implement proper input validation and sanitization mechanisms. When processing certain HTTP requests, the web server directly incorporates user-controlled data into system command execution contexts without adequately filtering or escaping special characters and command sequences.

This type of vulnerability typically arises when:

• User input is concatenated directly into shell commands
• Special shell metacharacters (;, |, &, $(), backticks) are not stripped or escaped
• No allowlist validation restricts input to expected values
• The application runs with elevated privileges, amplifying the impact of successful injection

Attack Vector

The attack vector for CVE-2021-36260 is network-based and requires no authentication. An attacker sends a maliciously crafted HTTP request to the vulnerable device's web interface. The request contains embedded operating system commands within parameters that the web server processes without proper sanitization.

The vulnerability can be exploited through specially crafted messages sent to the web server. The injected commands execute in the security context of the web server process, which typically runs as root on these embedded Linux-based devices. This allows attackers to:

1. Execute arbitrary shell commands remotely
2. Download and execute additional malicious payloads
3. Establish persistent backdoor access
4. Exfiltrate sensitive data including video streams
5. Modify device configurations to disable security features
6. Pivot to attack other devices on the internal network

Technical details regarding specific exploitation techniques are available through the Packet Storm Command Injection advisory and the Packet Storm Unauthenticated Command Injection advisory.

Detection Methods for CVE-2021-36260

Indicators of Compromise

• Unexpected outbound network connections from Hikvision devices to unknown external IP addresses
• Unusual processes or shell commands executing on the device (if logs are accessible)
• Modified device configurations such as disabled authentication or changed network settings
• Presence of unfamiliar files or scripts in device storage
• Device exhibiting abnormal behavior such as increased CPU usage, unexpected reboots, or degraded performance

Detection Strategies

• Monitor network traffic to and from Hikvision devices for anomalous HTTP requests containing shell metacharacters or command sequences
• Implement intrusion detection/prevention system (IDS/IPS) rules to detect CVE-2021-36260 exploitation attempts
• Review web server access logs for suspicious request patterns targeting known vulnerable endpoints
• Use network segmentation monitoring to detect lateral movement attempts originating from camera network segments

Monitoring Recommendations

• Isolate IoT and surveillance devices on dedicated VLANs with restricted access to critical network resources
• Deploy network traffic analysis tools to baseline normal device behavior and alert on deviations
• Implement egress filtering to block unauthorized outbound connections from surveillance devices
• Regularly audit device configurations for unauthorized changes

How to Mitigate CVE-2021-36260

Immediate Actions Required

• Apply firmware updates from Hikvision immediately to patch vulnerable devices
• If patching is not immediately possible, restrict network access to vulnerable devices using firewall rules
• Disable remote access to device web interfaces from untrusted networks, particularly the internet
• Implement network segmentation to isolate surveillance devices from critical infrastructure
• Monitor affected devices for signs of compromise while remediation is in progress

Patch Information

Hikvision has released firmware updates to address CVE-2021-36260 across affected product lines. Organizations should consult the Hikvision Security Advisory for the specific patched firmware versions applicable to their deployed devices. Firmware updates should be downloaded only from official Hikvision channels to avoid supply chain compromise risks.

Given that this vulnerability is listed in the CISA Known Exploited Vulnerabilities Catalog, federal agencies are mandated to remediate within specified timeframes, and all organizations are strongly encouraged to prioritize patching.

Workarounds

• Block direct internet access to Hikvision device web interfaces using perimeter firewalls
• Implement strict access control lists (ACLs) to limit which hosts can communicate with camera management ports
• Use VPN connections for any required remote administration rather than exposing devices directly
• Consider disabling the web interface entirely if alternative management methods are available
• Deploy web application firewalls (WAFs) in front of devices if direct patching is delayed

# Example firewall rule to restrict Hikvision camera access (iptables)
# Allow access only from management subnet
iptables -A INPUT -p tcp --dport 80 -s 10.0.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.0.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP