Weakness · Medium
CWE-454: External Initialization of Trusted Variables or Data Stores
What it is
The product initializes critical internal variables or data stores using inputs that can be modified by untrusted actors.
- Severity (our rating)
- Medium
- Likelihood of exploit
- Not rated by MITRE
- Introduced during
- Architecture and Design, Implementation
- Exploited in the wild
- No CVE in CISA's catalog
In more detail
A product system should be reluctant to trust variables that have been initialized outside of its trust boundary, especially if they are initialized by users. The variables may have been initialized incorrectly. If an attacker can initialize the variable, then they can influence what the vulnerable system will do.
What an attacker can do
- Modify Application Data (Integrity)
How to prevent it
Implementation
- A product system should be reluctant to trust variables that have been initialized outside of its trust boundary. Ensure adequate checking (e.g. input validation) is performed when relying on input from outside a trust boundary.
Architecture and Design
- Avoid any external control of variables. If necessary, restrict the variables that can be modified using an allowlist, and use a different namespace or naming convention if possible.
How to find it
- Automated Static Analysis. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.