Summary
A critical command injection flaw affects the File Transfer functionality in OpenSpug Spug versions up to the reported 3.4.0/4.0.1 releases. A remote attacker may be able to manipulate processing at /exec/transfer so that operating-system commands are executed by the server.
A critical command injection flaw affects the File Transfer functionality in OpenSpug Spug versions up to the reported 3.4.0/4.0.1 releases. A remote attacker may be able to manipulate processing at /exec/transfer so that operating-system commands are executed by the server.
Affected context
The issue occurs in Spug's File Transfer component at the /exec/transfer endpoint. Risk is elevated when the endpoint is remotely reachable and user-controlled transfer data is incorporated into operating-system command execution without sufficiently strict separation between data and commands.
The issue occurs in Spug's File Transfer component at the /exec/transfer endpoint. Risk is elevated when the endpoint is remotely reachable and user-controlled transfer data is incorporated into operating-system command execution without sufficiently strict separation between data and commands.
Exploit preconditions
- Attack surface: The remotely reachable File Transfer endpoint
- Required access: Network access to the affected Spug service; authentication requirements depend on deployment configuration
- Trigger point: Processing a manipulated request through
/exec/transfer - Why exploitation is possible: Untrusted input may reach an operating-system command execution path without adequate command and argument isolation
- Attack surface: The remotely reachable File Transfer endpoint
- Required access: Network access to the affected Spug service; authentication requirements depend on deployment configuration
- Trigger point: Processing a manipulated request through
/exec/transfer - Why exploitation is possible: Untrusted input may reach an operating-system command execution path without adequate command and argument isolation
Why this happens
The underlying bug is an OS command injection condition, mapped primarily to CWE-78: Improper Neutralization of Special Elements used in an OS Command. The application appears to pass externally influenced transfer parameters into a system command or command interpreter without consistently treating them as data. CWE-77 is also relevant because the broader weakness involves improper neutralization of special elements used in dynamically constructed commands.
The underlying bug is an OS command injection condition, mapped primarily to CWE-78: Improper Neutralization of Special Elements used in an OS Command. The application appears to pass externally influenced transfer parameters into a system command or command interpreter without consistently treating them as data. CWE-77 is also relevant because the broader weakness involves improper neutralization of special elements used in dynamically constructed commands.
Potential impact
- An attacker may execute operating-system commands under the application's account
- The service could be compromised or disrupted
- Confidential files and credentials may be exposed
- Data could be modified, deleted, or transferred
- The host or connected infrastructure could face lateral movement or further compromise
- An attacker may execute operating-system commands under the application's account
- The service could be compromised or disrupted
- Confidential files and credentials may be exposed
- Data could be modified, deleted, or transferred
- The host or connected infrastructure could face lateral movement or further compromise
General mitigation guidance
Mitigation generally centers on removing shell interpretation from file-transfer workflows and reducing trust in request-controlled values.
Common defensive patterns include:
- Prefer direct process or library APIs that pass fixed arguments without invoking a shell
- Apply strict allowlists and typed validation to filenames, paths, transfer modes, and other parameters
- Avoid constructing commands through string concatenation or interpolation
- Use dedicated file-transfer abstractions with secure path handling
- Run the service with least-privilege operating-system and application permissions
- Restrict endpoint exposure and require strong authorization for file-transfer operations
- Log security-relevant transfer activity and reject unexpected input by default
Mitigation generally centers on removing shell interpretation from file-transfer workflows and reducing trust in request-controlled values.
Common defensive patterns include:
- Prefer direct process or library APIs that pass fixed arguments without invoking a shell
- Apply strict allowlists and typed validation to filenames, paths, transfer modes, and other parameters
- Avoid constructing commands through string concatenation or interpolation
- Use dedicated file-transfer abstractions with secure path handling
- Run the service with least-privilege operating-system and application permissions
- Restrict endpoint exposure and require strong authorization for file-transfer operations
- Log security-relevant transfer activity and reject unexpected input by default
How teams detect issues like this
Detection can combine static analysis, review, runtime monitoring, and policy controls.
Useful approaches include:
- Search for shell invocation APIs, command interpreters, and string-built commands in the File Transfer code path
- Flag concatenation or interpolation of request parameters into process arguments or command strings
- Review whether filenames and transfer options are validated against strict allowlists
- Monitor endpoint requests, child-process creation, unusual command execution, and unexpected outbound connections
- Enforce code-scanning and dependency-review policies that identify command-injection patterns
- Use automated security review tools as a supplementary signal rather than a replacement for manual analysis
Detection can combine static analysis, review, runtime monitoring, and policy controls.
Useful approaches include:
- Search for shell invocation APIs, command interpreters, and string-built commands in the File Transfer code path
- Flag concatenation or interpolation of request parameters into process arguments or command strings
- Review whether filenames and transfer options are validated against strict allowlists
- Monitor endpoint requests, child-process creation, unusual command execution, and unexpected outbound connections
- Enforce code-scanning and dependency-review policies that identify command-injection patterns
- Use automated security review tools as a supplementary signal rather than a replacement for manual analysis
Sources
| Source | Link |
|---|---|
| github. | github.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
