CWE-912: Hidden Functionality
Official CWE-912 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-912: Hidden Functionality
Hidden Functionality represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Other,Integrity: Varies by Context,Alter Execution Logic
Developer Pattern
CWE-912 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Confidence
high confidence from CWE-912, 4.20.
Official CWE Definition
CWE-912: Hidden Functionality
The product contains functionality that is not documented, not part of the specification, and not accessible through an interface or command sequence that is obvious to the product's users or administrators.
Hidden functionality can take many forms, such as intentionally malicious code, "Easter Eggs" that contain extraneous functionality such as games, developer-friendly shortcuts that reduce maintenance or support costs such as hard-coded accounts, etc. From a security perspective, even when the functionality is not intentionally malicious or damaging, it can increase the product's attack surface and expose additional weaknesses beyond what is already exposed by the intended functionality. Even if it is not easily accessible, the hidden functionality could be useful for attacks that modify the control flow of the application.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- In the example below, a malicous developer has injected code to send credit card numbers to the developer's own email address.
- Consider a device that comes with various security measures, such as secure boot. The secure-boot process performs firmware-integrity verification at boot time, and this code is stored in a separate SPI-flash device. However, this code contains undocumented "special access features" intended to be used only for performing failure analysis and intended to only be unlocked by the device designer. Remove all chicken bits and hidden features that are exposed to attackers. Add authorization schemes that rely on cryptographic primitives to access any features that the manufacturer does not want to expose. Clearly document all interfaces.
Remediation
- Installation: Always verify the integrity of the product that is being installed.
Detection
- Automated Static Analysis: Conduct a code coverage analysis using live testing, then closely inspect any code that is not covered.
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.