CWE-7

Variant Abstraction Level
Pillar — Highest-level weakness category
Class — Abstract, language-independent
Base — Specific enough to detect
Variant — Tied to specific technology
Compound — Requires multiple weaknesses Incomplete MITRE CWE Status
Stable — Fully reviewed and complete
Draft — Under development, may change
Incomplete — Partially defined by MITRE
Deprecated — No longer recommended
Obsolete — Replaced by another CWE
J2EE Misconfiguration: Missing Custom Error Page

Description

The default error page of a web application should not display sensitive information about the product.

A Web application must define a default error page for 4xx errors (e.g. 404), 5xx (e.g. 500) errors and catch java.lang.Throwable exceptions to prevent attackers from mining information from the application container's built-in error response. When an attacker explores a web site looking for vulnerabilities, the amount of information that the site provides is crucial to the eventual success or failure of any attempted attacks.

Consequences

Confidentiality — Read Application Data

A stack trace might show the attacker a malformed SQL query string, the type of database being used, and the version of the application container. This information enables the attacker to target known vulnerabilities in these components.

Mitigations

Phase: Implementation

Handle exceptions appropriately in source code.

Phase: Implementation, System Configuration

Always define appropriate error pages. The application configuration should specify a default error page in order to guarantee that the application will never leak error messages to an attacker. Handling standard HTTP error codes is useful and user-friendly in addition to being a good security practice, and a good configuration will also define a last-chance error handler that catches any exception that could possibly be thrown by the application.

Phase: Implementation

Do not attempt to process an error or attempt to mask it.

Phase: Implementation

Verify return values are correct and do not supply sensitive information about the system.