Annke Network Video Recorder

1. EXECUTIVE SUMMARY

• CVSS v3 9.4
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Annke
• Equipment: N48PBB (NVR)
• Vulnerability: Stack-based Buffer Overflow

2. RISK EVALUATION

Successful exploitation of this vulnerability may cause a stack-based buffer overflow, which could allow an unauthenticated remote attacker access to sensitive information and execute arbitrary code.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

This vulnerability affects following versions of N48PBB (NVR):

• V3.4.106 build 200422 and prior

3.2 VULNERABILITY OVERVIEW

3.2.1    STACK-BASED BUFFER OVERFLOW CWE-121

The affected products are vulnerable to a stack-based buffer overflow, which allows an unauthorized remote attacker to execute arbitrary code with the same privileges as the server user (root).

CVE-2021-32941 has been assigned to this vulnerability. A CVSS v3 base score of 9.4 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H).

3.3 BACKGROUND

CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities

COUNTRIES/AREAS DEPLOYED: Worldwide

COMPANY HEADQUARTERS LOCATION: China

3.4 RESEARCHER

Andrea Palanca from Nozomi Networks reported this vulnerability to CISA.

4. MITIGATIONS

Annke recommends users update to the latest version.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
• When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.



CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.



Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability.

• Annke