Summary
A command injection vulnerability in the TRENDnet TEW-751DR, TEW-752DRU, and TEW733GR web management backend allows attacker-controlled input in the service argument to reach operating system command execution.
Because the affected function is remotely accessible, an unauthenticated or otherwise unauthorized network attacker may be able to execute commands on an exposed router, depending on the device's management access controls.
A command injection vulnerability in the TRENDnet TEW-751DR, TEW-752DRU, and TEW733GR web management backend allows attacker-controlled input in the service argument to reach operating system command execution.
Because the affected function is remotely accessible, an unauthenticated or otherwise unauthorized network attacker may be able to execute commands on an exposed router, depending on the device's management access controls.
Affected context
The vulnerability occurs in the Web Management Backend, specifically the pigwidgeon.cgi component and its handling of the service argument. It affects identified firmware versions of the TRENDnet TEW-751DR, TEW-752DRU, and TEW733GR product lines, which were discontinued and are no longer supported by the maintainer. Risk is greatest when the router's web management interface is reachable from an untrusted network.
The vulnerability occurs in the Web Management Backend, specifically the pigwidgeon.cgi component and its handling of the service argument. It affects identified firmware versions of the TRENDnet TEW-751DR, TEW-752DRU, and TEW733GR product lines, which were discontinued and are no longer supported by the maintainer. Risk is greatest when the router's web management interface is reachable from an untrusted network.
Exploit preconditions
- Attack surface: The router's remotely reachable web management interface
- Required access: Network access to the affected management endpoint; authentication requirements may depend on device configuration
- Trigger point: Processing of the
serviceargument bypigwidgeon.cgi - Why exploitation is possible: Input is incorporated into an operating system command without sufficient separation, validation, or neutralization of shell-sensitive content
- Attack surface: The router's remotely reachable web management interface
- Required access: Network access to the affected management endpoint; authentication requirements may depend on device configuration
- Trigger point: Processing of the
serviceargument bypigwidgeon.cgi - Why exploitation is possible: Input is incorporated into an operating system command without sufficient separation, validation, or neutralization of shell-sensitive content
Why this happens
The underlying flaw is OS command injection, mapped primarily to CWE-78: Improper Neutralization of Special Elements used in an OS Command. The backend treats externally supplied data as part of a command or command argument rather than as strictly bounded data, allowing control characters or metacharacters to alter command interpretation. The related CWE-77 classification reflects the broader command-construction and command-injection weakness.
The underlying flaw is OS command injection, mapped primarily to CWE-78: Improper Neutralization of Special Elements used in an OS Command. The backend treats externally supplied data as part of a command or command argument rather than as strictly bounded data, allowing control characters or metacharacters to alter command interpretation. The related CWE-77 classification reflects the broader command-construction and command-injection weakness.
Potential impact
- An attacker could execute arbitrary commands with the privileges of the web management process
- The router could be taken over or rendered unavailable
- Network traffic could be monitored, redirected, or disrupted
- Administrative credentials or configuration data could be exposed
- The device could be used for lateral movement, persistence, or participation in additional attacks
- An attacker could execute arbitrary commands with the privileges of the web management process
- The router could be taken over or rendered unavailable
- Network traffic could be monitored, redirected, or disrupted
- Administrative credentials or configuration data could be exposed
- The device could be used for lateral movement, persistence, or participation in additional attacks
General mitigation guidance
Mitigation generally focuses on removing shell interpretation from request handling and reducing exposure of unsupported network appliances.
Common defensive patterns include:
- Replacing shell-based command construction with fixed, parameterized APIs
- Applying strict allowlist validation to service-related values
- Separating data from commands and avoiding shell invocation where possible
- Restricting management interfaces to trusted administration networks
- Enforcing strong authentication, network segmentation, and least-privilege service accounts
- Isolating or replacing end-of-life devices when vendor remediation and security testing are unavailable
- Monitoring and restricting outbound connections from router management services
Mitigation generally focuses on removing shell interpretation from request handling and reducing exposure of unsupported network appliances.
Common defensive patterns include:
- Replacing shell-based command construction with fixed, parameterized APIs
- Applying strict allowlist validation to service-related values
- Separating data from commands and avoiding shell invocation where possible
- Restricting management interfaces to trusted administration networks
- Enforcing strong authentication, network segmentation, and least-privilege service accounts
- Isolating or replacing end-of-life devices when vendor remediation and security testing are unavailable
- Monitoring and restricting outbound connections from router management services
How teams detect issues like this
Organizations commonly look for this weakness through:
- Static analysis rules identifying user-controlled values passed to shell execution or command-building functions
- Code review checks for CGI parameters reaching
system,exec,popen,fwrite-based command paths, or equivalent process APIs - Web application firewall and network monitoring rules for suspicious requests targeting legacy management endpoints
- Configuration audits confirming that router administration is not exposed to untrusted networks
- Firmware and asset inventories identifying unsupported TRENDnet devices
Automated security review tools may help identify command-construction paths, but findings should be validated against the device's actual request flow.
Organizations commonly look for this weakness through:
- Static analysis rules identifying user-controlled values passed to shell execution or command-building functions
- Code review checks for CGI parameters reaching
system,exec,popen,fwrite-based command paths, or equivalent process APIs - Web application firewall and network monitoring rules for suspicious requests targeting legacy management endpoints
- Configuration audits confirming that router administration is not exposed to untrusted networks
- Firmware and asset inventories identifying unsupported TRENDnet devices
Automated security review tools may help identify command-construction paths, but findings should be validated against the device's actual request flow.
Sources
| Source | Link |
|---|---|
| github. | github.com/ |
| github. | github.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
