Summary
A critical command injection vulnerability in the TOTOLINK A950RG Cloud Upgrade component allows attacker-controlled firmware filename input to influence command execution. Because the attack can be initiated remotely, a reachable management or upgrade service may enable unauthorized operating-system commands on the router.
A critical command injection vulnerability in the TOTOLINK A950RG Cloud Upgrade component allows attacker-controlled firmware filename input to influence command execution. Because the attack can be initiated remotely, a reachable management or upgrade service may enable unauthorized operating-system commands on the router.
Affected context
The vulnerability affects TOTOLINK A950RG devices running firmware version 4.1.2cu.5268_B20221104 when the Cloud Upgrade functionality invokes setCloudUpgradeFW in lib/cste_modules/upgrade.so. Risk depends on whether the relevant upgrade interface is remotely reachable and whether attacker-supplied FileName values are processed without adequate command or argument separation.
The vulnerability affects TOTOLINK A950RG devices running firmware version 4.1.2cu.5268_B20221104 when the Cloud Upgrade functionality invokes setCloudUpgradeFW in lib/cste_modules/upgrade.so. Risk depends on whether the relevant upgrade interface is remotely reachable and whether attacker-supplied FileName values are processed without adequate command or argument separation.
Exploit preconditions
- Attack surface: The device's remotely reachable Cloud Upgrade functionality
- Required access: Network access to the interface or service that accepts upgrade-related requests; authentication requirements depend on device configuration
- Trigger point: Processing of the
FileNameargument bysetCloudUpgradeFW - Why exploitation is possible: Attacker-controlled input reaches an operating-system command context without sufficient neutralization or strict parameterization
- Attack surface: The device's remotely reachable Cloud Upgrade functionality
- Required access: Network access to the interface or service that accepts upgrade-related requests; authentication requirements depend on device configuration
- Trigger point: Processing of the
FileNameargument bysetCloudUpgradeFW - Why exploitation is possible: Attacker-controlled input reaches an operating-system command context without sufficient neutralization or strict parameterization
Why this happens
The underlying bug is an injection flaw in the construction or execution of an operating-system command using externally controlled filename data. When input is concatenated into a shell command or otherwise interpreted as command syntax, control characters can alter the intended operation and cause additional commands to execute. 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 underlying bug is an injection flaw in the construction or execution of an operating-system command using externally controlled filename data. When input is concatenated into a shell command or otherwise interpreted as command syntax, control characters can alter the intended operation and cause additional commands to execute. 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 arbitrary commands with the privileges of the affected service
- The device could be modified, disabled, or used to intercept or redirect network traffic
- Configuration data, credentials, or connected-network information could be exposed
- The compromised router could support lateral movement into adjacent systems
- Persistence or malicious firmware-related changes could be introduced
- An attacker may execute arbitrary commands with the privileges of the affected service
- The device could be modified, disabled, or used to intercept or redirect network traffic
- Configuration data, credentials, or connected-network information could be exposed
- The compromised router could support lateral movement into adjacent systems
- Persistence or malicious firmware-related changes could be introduced
General mitigation guidance
Mitigation generally focuses on eliminating shell interpretation and reducing trust in upgrade parameters.
Common defensive patterns include:
- Passing filenames and arguments through APIs that do not invoke a shell
- Applying strict allowlist validation for filenames, paths, and supported firmware artifacts
- Separating data from commands through structured process-execution interfaces
- Restricting Cloud Upgrade exposure to trusted management networks where feasible
- Running upgrade services with the minimum privileges required
- Protecting firmware artifacts with authenticity and integrity verification
- Applying network segmentation and limiting administrative interfaces
Mitigation generally focuses on eliminating shell interpretation and reducing trust in upgrade parameters.
Common defensive patterns include:
- Passing filenames and arguments through APIs that do not invoke a shell
- Applying strict allowlist validation for filenames, paths, and supported firmware artifacts
- Separating data from commands through structured process-execution interfaces
- Restricting Cloud Upgrade exposure to trusted management networks where feasible
- Running upgrade services with the minimum privileges required
- Protecting firmware artifacts with authenticity and integrity verification
- Applying network segmentation and limiting administrative interfaces
How teams detect issues like this
Detection approaches can include:
- Static analysis for string concatenation or formatting of user input into shell commands
- Code review checks for command execution APIs receiving request parameters without strict validation
- Runtime monitoring for unusual process creation by the Cloud Upgrade component
- Network monitoring for unexpected access to firmware-management endpoints
- Policy enforcement requiring argument-safe process APIs and allowlisted upgrade inputs
- Automated security review tools that identify command construction and injection patterns
Detection approaches can include:
- Static analysis for string concatenation or formatting of user input into shell commands
- Code review checks for command execution APIs receiving request parameters without strict validation
- Runtime monitoring for unusual process creation by the Cloud Upgrade component
- Network monitoring for unexpected access to firmware-management endpoints
- Policy enforcement requiring argument-safe process APIs and allowlisted upgrade inputs
- Automated security review tools that identify command construction and injection patterns
Sources
| Source | Link |
|---|---|
| gist. | gist.github.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| totolink. | totolink.net/ |
