CVE-2024-29948: Hikvision NVR DoS Vulnerability

CVE-2024-29948 Overview

CVE-2024-29948 is an out-of-bounds read vulnerability affecting certain Hikvision Network Video Recorder (NVR) devices. An authenticated attacker with high privileges can exploit this vulnerability by sending specially crafted messages to a vulnerable device, potentially causing a service abnormality. This vulnerability falls under CWE-125 (Out-of-bounds Read), which occurs when software reads data past the boundary of an allocated buffer.

Critical Impact

Authenticated attackers with administrative access can trigger out-of-bounds read conditions, potentially leading to information disclosure and service disruption on affected Hikvision NVR devices.

Affected Products

• Hikvision NVR devices (specific models detailed in vendor advisory)
• Network Video Recorder firmware versions prior to security patch

Discovery Timeline

• 2024-04-02 - CVE-2024-29948 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-29948

Vulnerability Analysis

This out-of-bounds read vulnerability exists in certain Hikvision NVR devices and can be triggered by an authenticated attacker with high-level privileges. The vulnerability allows reading memory beyond the intended buffer boundaries when processing specially crafted messages. While exploitation requires authentication and elevated privileges, successful attacks can result in limited confidentiality impact through potential information disclosure and limited availability impact through service disruption.

The attack can be executed remotely over the network without requiring user interaction. However, the requirement for high privileges significantly limits the attack surface, as an adversary would need valid administrative credentials before attempting exploitation.

Root Cause

The root cause of CVE-2024-29948 is improper bounds checking when handling incoming messages on affected Hikvision NVR devices. When the device processes certain crafted input, it fails to properly validate the boundaries of memory access operations, leading to reads beyond the allocated buffer space. This is classified under CWE-125 (Out-of-bounds Read), a memory safety issue that can expose sensitive data stored in adjacent memory locations.

Attack Vector

The attack vector for this vulnerability is network-based, requiring the attacker to send specially crafted messages to the target NVR device. The exploitation scenario involves:

1. Authentication requirement: The attacker must first authenticate to the NVR device with high-privilege credentials (administrative access)
2. Message crafting: The attacker constructs malformed messages designed to trigger the out-of-bounds read condition
3. Remote delivery: The crafted messages are sent over the network to the vulnerable device
4. Impact: Successful exploitation may cause service abnormality and potentially leak limited memory contents

The vulnerability cannot be exploited by unauthenticated users or those with standard user privileges, which significantly reduces the risk of widespread exploitation. For detailed technical information, refer to the Hikvision Security Advisory.

Detection Methods for CVE-2024-29948

Indicators of Compromise

• Unexpected service crashes or restarts on NVR devices
• Anomalous authentication attempts followed by unusual network traffic patterns
• System logs showing repeated failed message processing errors
• Unusual memory-related error messages in device logs

Detection Strategies

• Monitor NVR device logs for service abnormality events and unexpected restarts
• Implement network monitoring to detect unusual traffic patterns to NVR management interfaces
• Review authentication logs for suspicious privileged account activity
• Deploy intrusion detection signatures to identify malformed message patterns targeting NVR devices

Monitoring Recommendations

• Enable comprehensive logging on all Hikvision NVR devices
• Configure alerting for administrative authentication events, especially from unusual source IPs
• Implement network segmentation to isolate NVR devices and monitor inter-segment traffic
• Regularly audit privileged account usage and access patterns

How to Mitigate CVE-2024-29948

Immediate Actions Required

• Review the Hikvision Security Advisory for affected device models and firmware versions
• Restrict network access to NVR device management interfaces to trusted IP addresses only
• Audit and minimize the number of accounts with high-privilege access
• Ensure strong authentication credentials are in place for all administrative accounts

Patch Information

Hikvision has released security patches addressing this vulnerability. Organizations should consult the official Hikvision Security Advisory for specific firmware versions containing the fix and detailed update instructions for affected NVR models.

Workarounds

• Implement network segmentation to isolate NVR devices from general network access
• Use firewall rules to restrict management interface access to specific administrator workstations
• Disable or restrict remote management access when not actively needed
• Enable multi-factor authentication where supported for administrative access

# Network segmentation example - restrict NVR management access
# Allow management access only from specific admin subnet
iptables -A INPUT -p tcp -s 192.168.10.0/24 --dport 443 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP