Summary
A SQL injection vulnerability in Zen Cart's PayPal IPN Handler allows attacker-controlled txn_id data to influence database operations through zen_db_perform.
Because the affected handler can be reached remotely, an attacker may manipulate database queries when crafted transaction notifications are processed.
A SQL injection vulnerability in Zen Cart's PayPal IPN Handler allows attacker-controlled txn_id data to influence database operations through zen_db_perform.
Because the affected handler can be reached remotely, an attacker may manipulate database queries when crafted transaction notifications are processed.
Affected context
The vulnerability occurs in Zen Cart deployments using the PayPal IPN Handler, particularly when remotely received transaction notifications are processed by includes/modules/payment/paypaldp.php. It becomes risky when the txn_id value reaches database-writing logic without being safely parameterized or otherwise constrained.
The vulnerability occurs in Zen Cart deployments using the PayPal IPN Handler, particularly when remotely received transaction notifications are processed by includes/modules/payment/paypaldp.php. It becomes risky when the txn_id value reaches database-writing logic without being safely parameterized or otherwise constrained.
Exploit preconditions
- Attack surface: PayPal IPN notification handling exposed through the application's remote request path
- Required access: Ability to send or influence an IPN-style request; normal authenticated application access may not be required
- Trigger point: Processing of the
txn_idargument by the PayPal IPN Handler - Why exploitation is possible: Attacker-controlled input may be incorporated into database operations without sufficient query separation or validation
- Attack surface: PayPal IPN notification handling exposed through the application's remote request path
- Required access: Ability to send or influence an IPN-style request; normal authenticated application access may not be required
- Trigger point: Processing of the
txn_idargument by the PayPal IPN Handler - Why exploitation is possible: Attacker-controlled input may be incorporated into database operations without sufficient query separation or validation
Why this happens
The underlying bug is an unsafe data-to-query flow in which the txn_id parameter can influence SQL statements used by zen_db_perform.
This behavior maps primarily to CWE-89: Improper Neutralization of Special Elements used in an SQL Command, commonly called SQL injection. The related CWE-74 classification reflects the broader failure to neutralize special elements within an interpreted command or language.
The underlying bug is an unsafe data-to-query flow in which the txn_id parameter can influence SQL statements used by zen_db_perform.
This behavior maps primarily to CWE-89: Improper Neutralization of Special Elements used in an SQL Command, commonly called SQL injection. The related CWE-74 classification reflects the broader failure to neutralize special elements within an interpreted command or language.
Potential impact
- An attacker may read or alter database records
- The application could experience unauthorized transaction or order-state changes
- Sensitive customer or configuration data could be exposed
- Database integrity could be damaged or fraud-related activity could be enabled
- Further compromise could be possible if the database account has excessive privileges
- An attacker may read or alter database records
- The application could experience unauthorized transaction or order-state changes
- Sensitive customer or configuration data could be exposed
- Database integrity could be damaged or fraud-related activity could be enabled
- Further compromise could be possible if the database account has excessive privileges
General mitigation guidance
Mitigation generally focuses on ensuring that external notification data cannot alter SQL syntax or command structure.
Common defensive patterns include:
- Use parameterized queries or prepared statements for all database operations
- Apply strict type, length, and format validation to transaction identifiers
- Prefer allowlisted input handling over blacklist-based filtering
- Keep database credentials limited to the operations required by the application
- Treat payment notifications as untrusted until authenticity and business-state checks are complete
- Avoid constructing SQL statements through string concatenation
Mitigation generally focuses on ensuring that external notification data cannot alter SQL syntax or command structure.
Common defensive patterns include:
- Use parameterized queries or prepared statements for all database operations
- Apply strict type, length, and format validation to transaction identifiers
- Prefer allowlisted input handling over blacklist-based filtering
- Keep database credentials limited to the operations required by the application
- Treat payment notifications as untrusted until authenticity and business-state checks are complete
- Avoid constructing SQL statements through string concatenation
How teams detect issues like this
Organizations can identify similar risks through:
- Static analysis rules for SQL string concatenation involving request parameters
- Code review checks covering payment callbacks, IPN handlers, and database helper calls
- Dynamic testing of notification endpoints with safely controlled malformed input
- Web application firewall or API policy rules monitoring anomalous database-oriented input patterns
- Database audit logging for unexpected query shapes, writes, or access to unrelated records
Organizations can identify similar risks through:
- Static analysis rules for SQL string concatenation involving request parameters
- Code review checks covering payment callbacks, IPN handlers, and database helper calls
- Dynamic testing of notification endpoints with safely controlled malformed input
- Web application firewall or API policy rules monitoring anomalous database-oriented input patterns
- Database audit logging for unexpected query shapes, writes, or access to unrelated records
Sources
| Source | Link |
|---|---|
| cdkkx. | cdkkx.github.io/ |
| github. | github.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
| vuldb. | vuldb.com/ |
