Bug 711463 (CVE-2011-2193)

User-Agent:       Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.2; .NET4.0C)

(This is the bug as submitted to the EGI SVG - see additional info.)
Hello,

I represent Polish NGI (security officer). I would like
to report a vulnerability we've found in Torque.
Below is my original email to Torque developers.
This issue concerns PBS Pro (at least last version) as well.

best regards
- -- 
Bartlomiej Balcerek
Wroclaw University of Technology, Poland
Wroclaw Centre for Networking and Supercomputing
phone: +48 (71) 320-20-79 mail: bartol.pl [lookup email] [lookup "pwr.wroc.pl"]



- ------ Wiadomość oryginalna ------
Temat: Security vulnerability in Torque
Data: Tue, 10 May 2011 10:11:19 +0200
Nadawca: Bartlomiej Balcerek <bartol.pl> [lookup email] [lookup "pwr.wroc.pl"]
Firma/Organizacja: WCSS, PWr.
Adresat: info [lookup email] [lookup "clusterresources.com"]
Kopia: maciej.kotowicz.pl [lookup email] [lookup "pwr.wroc.pl"], adam.zabrocki.pl [lookup email] [lookup "pwr.wroc.pl"]

Dear Sirs,

I represent Wroclaw Centre for Networking and Supercomputing Security
Team. Recently, during the security audit, we discovered a bug in
Torque server and pbs_iff (all versions) which can have serious
implications to security. This is likely to lead attacker to elevate his
privileges.

Torque server does not check the length of "job name" argument before
using it - this string is verified only on the client side. It is
possible to use modified Torque client or DRMAA interface to submit job
with arbitrary chosen job name in terms of length and content. Thus, it
is possible to attacker to overflow buffer and overwrite some Torque
server process internal data causing its specific behavior.

Below are some technical details concerning x86_64 build:

What can be overwritten is log_buffer global string array and
all next symbols:

0000000000734b00 B log_buffer
0000000000738b00 B msg_registerrel
0000000000738b08 B msg_manager
0000000000738b10 B msg_startup1
0000000000738b18 B msg_momnoexec1
0000000000738b20 B msg_man_uns
0000000000738b28 B msg_sched_nocall
0000000000738b30 B msg_issuebad
0000000000738b38 B stdout@@GLIBC_2.2.5
0000000000738b40 B msg_job_end_stat
0000000000738b48 b dtor_idx.6147
0000000000738b50 b completed.6145
0000000000738b58 b acct_opened
0000000000738b5c b acct_auto_switch
0000000000738b60 b acctfile
0000000000738b68 b acct_opened_day
0000000000738b70 b spaceused
0000000000738b78 b spaceavail
0000000000738b80 b username.6360
0000000000738bc0 b groupname.6402

Here I submit the crafted job:

[bartol@bartek_torque torque-mod]$ echo /bin/date | ./src/cmds/qsub -Z
"Job_Name=`perl -e 'print "A"x16350'`"

It is possible now to see in debugger that structures adjacent to
log_buffer are overwritten with "A" chars (encoded as 0x41 numbers):

Program received signal SIGINT, Interrupt.
0x00000033550cd323 in __select_nocancel () from /lib64/libc.so.6
(gdb) x/20x 0x0000000000738b00
0x738b00 <msg_registerrel>: 0x4141414141414141 0x4141414141414141
0x738b10 <msg_startup1>: 0x4141414141414141 0x4141414141414141
0x738b20 <msg_man_uns>: 0x4141414141414141 0x4141414141414141

The overflow occurs in the following code:

1560 sprintf(log_buffer, msg_jobnew,
1561 preq->rq_user, preq->rq_host,
1562 pj->ji_wattr[(int)JOB_ATR_job_owner].at_val.at_str,
1563 pj->ji_wattr[(int)JOB_ATR_jobname].at_val.at_str,
1564 pj->ji_qhdr->qu_qs.qu_name);

We proved that server crash is easily possible (including database
damage) and we think privilege escalation can be done with some more
effort as well, but the latter is strongly dependable on particular
build flags and architecture.

The overflow is also possible in pbs_iff setuid binary, since the "host"
variable length is not checked:

sprintf(log_buffer,"cannot resolve IP address for host '%s'
herror=%d: %s",
hostname, /*1*/
h_errno,
hstrerror(h_errno));


Please let us know if you need some additional information and what
are your plans concerning this issue.

Bartlomiej Balcerek
Maciej Kotowicz
Adam Zabrocki




Reproducible: Always




This problem was reported to the EGI Software Vulnerability Group  by Bartlomiej.Balcerek   (Bartlomiej.Balcerek.pl) rather than found by the submitter. It has also been reported to the Torque providers, and been fixed by them -  
an e-mail from Douglas Wightman  (wightman) states:

Dear Bartlomiej,

Thank you for the email.  I apologize that we did not reply sooner.  Our Torque engineers have patched this vulnerability in the latest releases of Torque (2.4 and higher).

We are working on getting you a new release that you can verify.  Please expect a follow-up email soon.

Thanks for your help with this issue and please continue to report all future issues that you may encounter.

Thanks,

- Douglas Wightman

This bug is being entered in order that a 'fixed' version of Torque is available in EPEL. 

The EGI http://www.egi.eu/ Software Vulnerability group  http://www.egi.eu/policy/groups/Software_Vulnerability_Group_SVG.html runs a process for handling software vulnerabilities reported. While our work is primarily designed to handle vulnerabilities in Grid Middleware, other vulnerabilities found in software used in the EGI infrastructure may also be reported to us and we pass the information on to the software suppliers, as well as considering the risk to the EGI infrastructure.