Description
An OS command injection vulnerability exists in white-labeled DVRs manufactured by TVT, affecting a custom HTTP service called "Cross Web Server" that listens on TCP ports 81 and 82. The web interface fails to sanitize input in the URI path passed to the language extraction functionality. When the server processes a request to /language/[lang]/index.html, it uses the [lang] input unsafely in a tar extraction command without proper escaping. This allows an unauthenticated remote attacker to inject shell commands and achieve arbitrary command execution as root.
EPSS Score:
1%
Comprehensive Technical Analysis of EUVD-2025-18965
1. Vulnerability Assessment and Severity Evaluation
The vulnerability described in EUVD-2025-18965 is an OS command injection flaw affecting white-labeled DVRs manufactured by TVT. This vulnerability is present in the "Cross Web Server" service, which listens on TCP ports 81 and 82. The issue arises from the failure to sanitize input in the URI path passed to the language extraction functionality, allowing an unauthenticated remote attacker to inject shell commands and achieve arbitrary command execution as root.
Severity Evaluation:
- CVSS Base Score: 10.0
- CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
The CVSS score of 10.0 indicates a critical vulnerability. The high severity is due to the ease of exploitation (low complexity, no authentication required) and the significant impact (high confidentiality, integrity, and availability impact).
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Unauthenticated Remote Access: An attacker can exploit this vulnerability without needing any authentication.
- Network Access: The attacker needs network access to the DVR's web interface on ports 81 or 82.
Exploitation Methods:
- Command Injection: By crafting a malicious URI path, an attacker can inject arbitrary shell commands. For example, sending a request to
/language/$(command)/index.htmlwhere$(command)is the injected command. - Automated Scripts: Attackers can use automated scripts to scan for vulnerable DVRs and exploit them en masse.
3. Affected Systems and Software Versions
Affected Systems:
- White-labeled DVRs manufactured by Shenzhen TVT.
- Specifically, the "Cross Web Server" service running on TCP ports 81 and 82.
Software Versions:
- The vulnerability affects all versions of the CCTV-DVR software that include the "Cross Web Server" service with the flawed language extraction functionality.
4. Recommended Mitigation Strategies
Immediate Mitigation:
- Network Segmentation: Isolate DVRs from public networks to limit exposure.
- Firewall Rules: Block access to ports 81 and 82 from untrusted networks.
- Patch Management: Apply vendor-provided patches as soon as they are available.
Long-Term Mitigation:
- Firmware Updates: Regularly update the DVR firmware to the latest version.
- Input Validation: Ensure that all input is properly sanitized and validated.
- Least Privilege: Run services with the least privilege necessary to minimize the impact of potential exploits.
5. Impact on European Cybersecurity Landscape
The widespread use of CCTV-DVRs in both residential and commercial settings makes this vulnerability particularly concerning. Unpatched systems can be exploited to:
- Compromise Security Systems: Attackers can disable or manipulate CCTV feeds.
- Data Exfiltration: Sensitive data stored on DVRs can be exfiltrated.
- Botnet Recruitment: Vulnerable DVRs can be recruited into botnets for DDoS attacks or other malicious activities.
Given the critical nature of the vulnerability, it poses a significant risk to the European cybersecurity landscape, particularly in sectors relying heavily on CCTV systems for security.
6. Technical Details for Security Professionals
Vulnerability Details:
- Affected Service: Cross Web Server
- Affected Ports: TCP 81 and 82
- Vulnerable Functionality: Language extraction in the URI path
- Exploit Mechanism: Unsanitized input in the URI path allows command injection.
Exploit Example:
curl -X GET "http://<DVR_IP>:81/language/$(command)/index.html"
Where $(command) is the injected shell command.
Detection:
- Network Monitoring: Monitor for unusual traffic patterns on ports 81 and 82.
- Log Analysis: Check web server logs for suspicious URI paths.
Response:
- Incident Response: Immediately isolate affected DVRs and apply patches.
- Forensic Analysis: Conduct a thorough analysis to determine the extent of the compromise and identify any exfiltrated data.
References:
By addressing this vulnerability promptly and comprehensively, organizations can mitigate the risk of exploitation and ensure the integrity and security of their CCTV systems.