CWE-828: Signal Handler with Functionality that is not Asynchronous-Safe
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
The product defines a signal handler that contains code sequences that are not asynchronous-safe, i.e., the functionality is not reentrant, or it can be interrupted.
常见后果
影响范围: Integrity Confidentiality Availability
技术影响: DoS: Crash, Exit, or Restart Execute Unauthorized Code or Commands
说明: The most common consequence will be a corruption of the state of the product, possibly leading to a crash or exit. However, if the signal handler is operating on state variables for security relevant libraries or protection mechanisms, the consequences can be far more severe, including protection mechanism bypass, privilege escalation, or information exposure.
潜在缓解措施
阶段: Implementation Architecture and Design
有效性: High
阶段: Implementation
描述: Where non-reentrant functionality must be leveraged within a signal handler, be sure to block or mask signals appropriately. This includes blocking other signals within the signal handler itself that may also leverage the functionality. It also includes blocking all signals reliant upon the functionality when it is being accessed or modified by the normal behaviors of the product.
观察示例
参考: CVE-2008-4109
Signal handler uses functions that ultimately call the unsafe syslog/malloc/s*printf, leading to denial of service via multiple login attempts
参考: CVE-2006-5051
Chain: Signal handler contains too much functionality (CWE-828), introducing a race condition (CWE-362) that leads to a double free (CWE-415).
参考: CVE-2001-1349
unsafe calls to library functions from signal handler
参考: CVE-2004-0794
SIGURG can be used to remotely interrupt signal handler; other variants exist.
参考: CVE-2004-2259
SIGCHLD signal to FTP server can cause crash under heavy load while executing non-reentrant functions like malloc/free.
参考: CVE-2002-1563
SIGCHLD not blocked in a daemon loop while counter is modified, causing counter to get out of sync.
分类映射
| 分类名称 | 条目ID | 条目名称 | 映射适配度 |
|---|---|---|---|
| CERT C Secure Coding | SIG31-C | Do not access or modify shared objects in signal handlers | - |