CWE-479: Signal Handler Use of a Non-reentrant Function
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
The product defines a signal handler that calls a non-reentrant function.
常见后果
影响范围: Integrity Confidentiality Availability
技术影响: Execute Unauthorized Code or Commands
说明: It may be possible to execute arbitrary code through the use of a write-what-where condition.
影响范围: Integrity
技术影响: Modify Memory Modify Application Data
说明: Signal race conditions often result in data corruption.
潜在缓解措施
阶段: Requirements
描述: Require languages or libraries that provide reentrant functionality, or otherwise make it easier to avoid this weakness.
阶段: Architecture and Design
描述: Design signal handlers to only set flags rather than perform complex functionality.
阶段: Implementation
描述: Ensure that non-reentrant functions are not found in signal handlers.
阶段: Implementation
描述: Use sanity checks to reduce the timing window for exploitation of race conditions. This is only a partial solution, since many attacks might fail, but other attacks still might work within the narrower window, even accidentally.
有效性: Defense in Depth
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-2005-0893
signal handler calls function that ultimately uses malloc()
参考: CVE-2004-2259
SIGCHLD signal to FTP server can cause crash under heavy load while executing non-reentrant functions like malloc/free.
引入模式
| 阶段 | 说明 |
|---|---|
| Implementation | - |
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 |
|---|---|---|---|
| CLASP | - | Unsafe function call from a signal handler | - |
| CERT C Secure Coding | SIG30-C | Call only asynchronous-safe functions within signal handlers | Exact |
| CERT C Secure Coding | SIG34-C | Do not call signal() from within interruptible signal handlers | - |
| The CERT Oracle Secure Coding Standard for Java (2011) | EXP01-J | Never dereference null pointers | - |
| Software Fault Patterns | SFP3 | Use of an improper API | - |