2493 vulnerabilities classified as CWE-416 (释放后使用). AI Chinese analysis included.
CWE-416, Use After Free, is a critical memory safety weakness occurring when a program continues to reference a memory location after it has been deallocated. Attackers typically exploit this vulnerability by freeing an object and then rapidly reallocating that same memory block with attacker-controlled data. Because the original pointer still points to the now-invalid address, the application may inadvertently execute malicious code or corrupt memory structures, often leading to arbitrary code execution or denial of service. To prevent this, developers must rigorously manage memory lifecycles by nullifying pointers immediately after freeing them, ensuring no dangling references remain. Utilizing modern programming languages with automatic garbage collection or employing static analysis tools to detect invalid memory accesses further mitigates the risk, ensuring that freed memory is never accessed again during the program’s execution.
#include <stdio.h> #include <unistd.h> #define BUFSIZER1 512 #define BUFSIZER2 ((BUFSIZER1/2) - 8) int main(int argc, char **argv) { char *buf1R1; char *buf2R1; char *buf2R2; char *buf3R2; buf1R1 = (char *) malloc(BUFSIZER1); buf2R1 = (char *) malloc(BUFSIZER1); free(buf2R1); buf2R2 = (char *) malloc(BUFSIZER2); buf3R2 = (char *) malloc(BUFSIZER2); strncpy(buf2R1, argv[1], BUFSIZER1-1); free(buf1R1); free(buf2R2); free(buf3R2); }char* ptr = (char*)malloc (SIZE); if (err) { abrt = 1; free(ptr); } ... if (abrt) { logError("operation aborted before commit", ptr); }Vulnerabilities classified as CWE-416 (释放后使用) represent 2493 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.