CWE-336: Same Seed in Pseudo-Random Number Generator (PRNG)
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
A Pseudo-Random Number Generator (PRNG) uses the same seed each time the product is initialized.
扩展描述
Given the deterministic nature of PRNGs, using the same seed for each initialization will lead to the same output in the same order. If an attacker can guess (or knows) the seed, then the attacker may be able to determine the random numbers that will be produced from the PRNG.
常见后果
影响范围: Other Access Control
技术影响: Other Bypass Protection Mechanism
潜在缓解措施
阶段: Architecture and Design
描述: Do not reuse PRNG seeds. Consider a PRNG that periodically re-seeds itself as needed from a high quality pseudo-random output, such as hardware devices.
阶段: Architecture and Design Requirements
策略: Libraries or Frameworks
描述: Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems, or use the more recent FIPS 140-3 [REF-1192] if possible.
检测方法
方法: 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.)
有效性: High
观察示例
参考: CVE-2022-39218
SDK for JavaScript app builder for serverless code uses the same fixed seed for a PRNG, allowing cryptography bypass
引入模式
| 阶段 | 说明 |
|---|---|
| Implementation | REALIZATION: This weakness is caused during implementation of an architectural security tactic. |
适用平台
编程语言
分类映射
| 分类名称 | 条目ID | 条目名称 | 映射适配度 |
|---|---|---|---|
| PLOVER | - | Same Seed in PRNG | - |
| The CERT Oracle Secure Coding Standard for Java (2011) | MSC02-J | Generate strong random numbers | - |