CWE-908

Base 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 Exploit: Medium
Use of Uninitialized Resource

Description

The product uses or accesses a resource that has not been initialized.

When a resource has not been properly initialized, the product may behave unexpectedly. This may lead to a crash or invalid memory access, but the consequences vary depending on the type of resource and how it is used within the product.

Top Monitored CVEs

CVE-2025-5777
HIGH KEV
7.5 99.9%
2025-06-17
CVE-2023-24941
CRITICAL
9.8 94.7%
2023-05-09
CVE-2025-50165
CRITICAL
9.8 3.5%
2025-08-12
CVE-2024-38260
HIGH
8.8 1.6%
2024-09-10

Consequences

Confidentiality — Read Memory, Read Application Data

When reusing a resource such as memory or a program variable, the original contents of that resource may not be cleared before it is sent to an untrusted party.

Availability — DoS: Crash, Exit, or Restart

The uninitialized resource may contain values that cause program flow to change in ways that the programmer did not intend.

Mitigations

Phase: Implementation

Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.

Phase: Implementation

Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.

Phase: Implementation

Avoid race conditions (CWE-362) during initialization routines.

Phase: Build and Compilation

Run or compile the product with settings that generate warnings about uninitialized variables or data.

Detection

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.)