Summary
A command injection vulnerability in the DrayTek Vigor2960 Rename Table Handler allows attacker-controlled input in the newtable argument to influence command execution. Because the affected CGI function can be reached remotely, a network-accessible device may be at risk when requests reach the vulnerable handler.
A command injection vulnerability in the DrayTek Vigor2960 Rename Table Handler allows attacker-controlled input in the newtable argument to influence command execution. Because the affected CGI function can be reached remotely, a network-accessible device may be at risk when requests reach the vulnerable handler.
Affected context
The issue occurs in the rename_table function within /cgi-bin/mainfunction.cgi on affected Vigor2960 devices. Risk is higher when the management interface or CGI endpoint is reachable over a network and the handler processes the newtable parameter without sufficiently separating data from operating-system commands. The affected product is a legacy platform with limited maintainer support.
The issue occurs in the rename_table function within /cgi-bin/mainfunction.cgi on affected Vigor2960 devices. Risk is higher when the management interface or CGI endpoint is reachable over a network and the handler processes the newtable parameter without sufficiently separating data from operating-system commands. The affected product is a legacy platform with limited maintainer support.
Exploit preconditions
- Attack surface: Network-accessible web or CGI management interface
- Required access: Ability to send requests to the Rename Table Handler; the description does not establish whether authentication is required
- Trigger point: Processing of the
newtableargument by therename_tablefunction - Why exploitation is possible: Input reaches command-processing logic without adequate neutralization or strict validation, allowing command syntax to be interpreted by the underlying system
- Attack surface: Network-accessible web or CGI management interface
- Required access: Ability to send requests to the Rename Table Handler; the description does not establish whether authentication is required
- Trigger point: Processing of the
newtableargument by therename_tablefunction - Why exploitation is possible: Input reaches command-processing logic without adequate neutralization or strict validation, allowing command syntax to be interpreted by the underlying system
Why this happens
The vulnerability is caused by treating externally supplied table-name data as safe when it is incorporated into an operating-system command or command-like operation. Insufficient separation between data and executable command syntax allows special input to alter intended command behavior. This maps primarily to CWE-77: Improper Neutralization of Special Elements used in a Command, with CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component describing the broader injection pattern.
The vulnerability is caused by treating externally supplied table-name data as safe when it is incorporated into an operating-system command or command-like operation. Insufficient separation between data and executable command syntax allows special input to alter intended command behavior. This maps primarily to CWE-77: Improper Neutralization of Special Elements used in a Command, with CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component describing the broader injection pattern.
Potential impact
- An attacker may execute commands with the privileges of the affected service
- Device configuration or operational behavior could be altered
- Sensitive information may be accessed or modified
- The device could be used to attack other systems on reachable networks
- Service availability could be disrupted
- An attacker may execute commands with the privileges of the affected service
- Device configuration or operational behavior could be altered
- Sensitive information may be accessed or modified
- The device could be used to attack other systems on reachable networks
- Service availability could be disrupted
General mitigation guidance
Mitigation generally focuses on ensuring that table names remain data rather than executable command content.
Common defensive patterns include:
- Avoiding shell invocation for administrative operations where direct APIs or system calls are available
- Applying strict allowlist validation for table-name formats and permitted characters
- Using argument-safe process APIs with fixed command structures when external processes are unavoidable
- Limiting management interfaces to trusted networks and authenticated administrative channels
- Running management services with the minimum privileges required
- Applying vendor-maintained security fixes and retiring unsupported deployments where practical
- Monitoring and restricting outbound access from network appliances
Mitigation generally focuses on ensuring that table names remain data rather than executable command content.
Common defensive patterns include:
- Avoiding shell invocation for administrative operations where direct APIs or system calls are available
- Applying strict allowlist validation for table-name formats and permitted characters
- Using argument-safe process APIs with fixed command structures when external processes are unavoidable
- Limiting management interfaces to trusted networks and authenticated administrative channels
- Running management services with the minimum privileges required
- Applying vendor-maintained security fixes and retiring unsupported deployments where practical
- Monitoring and restricting outbound access from network appliances
How teams detect issues like this
Organizations commonly look for command-injection risks through:
- Static analysis rules identifying shell execution, command construction, or process-spawning APIs that receive request parameters
- Code review checks for string concatenation or interpolation involving CGI arguments
- Tests using boundary and metacharacter inputs in isolated environments to verify that values remain data
- Web application firewall and gateway policies that restrict unexpected command-like characters in administrative parameters
- Network monitoring for unusual management requests, command execution indicators, or unexpected outbound connections
- Automated security review tools that flag tainted data flowing from HTTP handlers into operating-system interfaces
Organizations commonly look for command-injection risks through:
- Static analysis rules identifying shell execution, command construction, or process-spawning APIs that receive request parameters
- Code review checks for string concatenation or interpolation involving CGI arguments
- Tests using boundary and metacharacter inputs in isolated environments to verify that values remain data
- Web application firewall and gateway policies that restrict unexpected command-like characters in administrative parameters
- Network monitoring for unusual management requests, command execution indicators, or unexpected outbound connections
- Automated security review tools that flag tainted data flowing from HTTP handlers into operating-system interfaces
