CVE-2025-34036 in CCTV-DVR
Summary
by MITRE • 06/24/2025
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. Exploitation evidence was observed by the Shadowserver Foundation on 2025-02-06 UTC.
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Analysis
by VulDB Data Team • 11/21/2025
This vulnerability represents a critical operating system command injection flaw in TVT white-labeled DVR devices that exposes a custom HTTP service known as "Cross Web Server" operating on TCP ports 81 and 82. The vulnerability stems from inadequate input validation within the language extraction functionality of the web server, specifically when processing URI paths that include language parameters. The affected system processes requests directed to paths following the pattern /language/[lang]/index.html where the [lang] parameter is directly incorporated into a tar extraction command without proper sanitization or escaping mechanisms. This design flaw creates a pathway for unauthenticated remote attackers to inject malicious shell commands through the language parameter, effectively bypassing normal security controls and gaining root-level system access. The vulnerability is particularly concerning as it affects network video recording devices that are often deployed in critical infrastructure environments where unauthorized access could lead to complete system compromise and potential data exfiltration or disruption of surveillance operations.
The technical exploitation of this vulnerability aligns with CWE-77 and CWE-78 categories, which specifically address command injection flaws where user-supplied input is improperly handled in system command execution contexts. According to the ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) as attackers can leverage the command injection to execute arbitrary code with root privileges. The vulnerability demonstrates a classic path traversal and command injection pattern where the language parameter becomes a vector for arbitrary code execution through the tar command. The fact that the vulnerability exists in a custom HTTP service rather than a standard web server component suggests that the device manufacturer may have implemented proprietary code that lacks proper security hardening measures. This type of vulnerability typically arises from insufficient input validation and improper use of system calls without appropriate escaping or sanitization of user-controllable data.
The operational impact of this vulnerability extends beyond simple remote code execution as it provides attackers with complete administrative control over the DVR systems. Given that these devices are commonly used in security-sensitive environments such as commercial buildings, industrial facilities, and residential properties, the compromise of such systems could result in unauthorized surveillance access, data manipulation, or complete system takeover. The vulnerability's exposure on ports 81 and 82 makes it particularly dangerous as these are non-standard ports that may not be properly monitored by network security devices or firewalls. The Shadowserver Foundation's observation of exploitation evidence on February 6, 2025, indicates that this vulnerability is actively being targeted by threat actors in the wild. Organizations using TVT DVR systems should consider immediate mitigation actions, as the vulnerability allows for complete system compromise without requiring authentication, making it an attractive target for attackers seeking persistent access to surveillance infrastructure.
Mitigation strategies should include immediate network segmentation to restrict access to ports 81 and 82, implementation of firewall rules to block external access to these ports, and deployment of network monitoring solutions to detect anomalous traffic patterns associated with command injection attempts. Device manufacturers should implement proper input sanitization and validation mechanisms for all user-controllable parameters, particularly those used in system command execution contexts. The implementation of proper escaping mechanisms for shell command arguments and adoption of secure coding practices that prevent direct command injection are essential. Organizations should also consider disabling unnecessary services and ports, applying firmware updates if available from the manufacturer, and implementing intrusion detection systems to monitor for exploitation attempts. Additionally, regular security assessments of networked devices should be conducted to identify similar vulnerabilities in other proprietary services or custom implementations that may be susceptible to similar command injection attacks.