Summary
A code injection vulnerability in Zhonglun CloudPos allows attacker-controlled URL input to reach the OpenLocalBrowser function in the JSBridge component. When the affected function processes a manipulated URL, a remote attacker may cause unintended code execution under the privileges of the application.
Affected context
The vulnerability occurs in Zhonglun CloudPos deployments up to version 3.0.1.76 where the JSBridge component exposes the OpenLocalBrowser function and accepts URL arguments without sufficiently restricting their content or behavior. Risk depends on whether an attacker can reach the relevant interface and provide or influence the URL value.
Exploit preconditions
- Attack surface: The JSBridge component and its OpenLocalBrowser function
- Required access: Network access to an exposed application interface that can influence the URL argument
- Trigger point: Processing of attacker-controlled input by OpenLocalBrowser
- Why exploitation is possible: The supplied URL is handled in a way that permits injected code or commands to be interpreted rather than treated solely as data
Why this happens
The underlying bug is insufficient separation between untrusted URL data and executable or interpreted content. The OpenLocalBrowser function appears to pass attacker-influenced input into a browser-launching or related execution path without adequate allowlisting, context-aware encoding, or validation. This maps primarily to CWE-94, Code Injection, with CWE-74 also relevant where special elements are accepted and interpreted by a downstream component.
Potential impact
- An attacker may execute code in the context of the affected application
- The vulnerability could enable unauthorized access to local data or services
- Application integrity and confidentiality may be compromised
- A compromised host could potentially be used for lateral movement or follow-on attacks
General mitigation guidance
Mitigation generally focuses on treating URL values as untrusted data and
preventing them from reaching executable or interpreted contexts.
Common defensive patterns include:
- Allowlisting permitted URL schemes, hosts, ports, and path formats
- Rejecting control characters, metacharacters, and unexpected URL encodings
- Using browser-launch APIs that do not invoke shell or interpreter processing
- Applying context-appropriate encoding and canonicalization before use
- Enforcing strict input schemas and validating after canonicalization
- Running the application with least privilege and isolating browser or helper processes
- Restricting network exposure of JSBridge interfaces where practical
How teams detect issues like this
Detection approaches may include:
- Static analysis for URL input flowing into process, shell, browser, or interpreter launch APIs
- Code review checks for string concatenation involving external URL values
- Verification that URL validation uses allowlists rather than blocklists
- Dynamic testing with malformed schemes, encoded delimiters, and unexpected URL components
- Runtime monitoring for unusual child-process creation or outbound connections from CloudPos
- CI policy checks that flag unsafe execution APIs and missing input validation
