Banning Users

During the CMS Security Challenge, glideinWMS CRAB SERVER operators may be asked to ban a particular DN and provide certain information about the "attack". In particular, given a particular user DN, admins may be asked to take action to:

Initial Actions

  • hold any running jobs
  • hold any queued jobs
  • block the user from further submissions

Detailed Procedures

The procedure for banning a user starts with mapping the certificate DN to a local userid on the UCSD CRAB Servers. This can be done by looking at the list of mappings. The command condor_q can also give you the same information, but only if the user still has jobs pending or running. The local UNIX userid typically has the form uscmsxxx. However, if a priority user's DN is compromised then it will have the form cmspaxxx.

condor_q -format '%s ' Owner -format '%s\n' x509userproxysubject | sort | uniq -c

On each of the submitter nodes (, submit-[1-4], HOLD any pending or running jobs from this user by running:

condor_hold uscmsxxx

As root, block the local userid in the /etc/passwd file on all submitter nodes by appending something to the userid like uscmsxxxBLOCKED. This will help in cleanup later. Effectively this will block any further submissions by denying the ability of the compromised DN to use gridftp on the server.

Collecting Information

Information an operator should collect:

  • which sites jobs from the banned user ran on
  • names of pilots which ran jobs from the banned user
  • incoming IP address from which jobs were submitted

Detailed Procedures

Information on which sites jobs ran at is in the condor logs on the submission nodes in the file /opt/glidecondor/condor_local/log/EventLog. The log contains event information in terms of condor cluster IDs, GLIDEIN_Site, time stamps etc.

We now have a tool to parse this log, courtesy of I. Sfiligoi. To use the tool (currently only installed on submit-4):

source /opt/condor_igor_3214/ 
condor_userlog -rotated -fullname -attr Owner,JOB_GLIDEIN_Site /opt/glidecondor/condor_local/log/EventLog
Job      Host            Start Time  Evict Time  Wall Time Good Time CPU Usage
31805.0  uscms3649,IFCA   8/28 20:43  8/28 20:44   0+00:01   0+00:01   0+00:00
31142.51 uscms4150,Louvain  8/28 20:29  8/28 23:01   0+02:32   0+00:00   0+00:00
31142.12 uscms4150,Louvain  8/28 20:59  8/28 23:01   0+02:02   0+00:00   0+00:00
31142.46 uscms4150,Louvain  8/28 20:58  8/28 23:02   0+02:03   0+00:00   0+00:00
31142.27 uscms4150,Louvain  8/28 21:01  8/28 23:02   0+02:01   0+00:00   0+00:00
31142.13 uscms4150,Louvain  8/28 21:02  8/28 23:02   0+02:00   0+00:00   0+00:00

To query a particular user:

condor_userlog -rotated -const 'Owner=="uscms2330"' -fullname -attr Owner,JOB_GLIDEIN_Site /opt/glidecondor/condor_local/log/EventLog
Job      Host            Start Time  Evict Time  Wall Time Good Time CPU Usage
31869.4  uscms2330,IFCA   8/29 00:20  8/29 00:21   0+00:01   0+00:01   0+00:00
31869.8  uscms2330,IFCA   8/29 00:20  8/29 00:21   0+00:01   0+00:01   0+00:00
31869.7  uscms2330,IFCA   8/29 00:20  8/29 00:21   0+00:01   0+00:01   0+00:00
31869.5  uscms2330,IFCA   8/29 00:20  8/29 00:21   0+00:01   0+00:01   0+00:00
31869.6  uscms2330,IFCA   8/29 00:20  8/29 00:21   0+00:01   0+00:01   0+00:00

Pilot startd names are also available in the EventLog. From this information it should be possible to determine which other jobs ran on the same pilots that may have been compromised, if any.

IP address from which jobs were submitted are more difficult to determine. In principle, this info is in two logs in $PRODAGENT_WORKDIR/CommandManager

  • ComponentLog says that there was e.g. a request to submit a new task.
  • FrontendLog says that IP n connected at time t.
However, there is no guaranteed relationship. FrontendLog is written by $CRABSERVER_ROOT/src/python/CommandManager/server_side/server2.c. S. Belforte looked a bit if it was obvious how to change to add the task name to the IP connection message (user's DN does not seem there, but task name would do), but it looks too complicted for understanding in a short time and we should not make very extensive changes to CRAB2 at this time.

Other actions based on information collected:

  • Notify sites where jobs ran. (Note that individual jobs could have run on more than one site! The new EventLog gives you this information, since it tracks condor events, not clusters.)
  • Report the results to CMS Security Contacts (Ian and Mine, and the cms-comp-security mailing list).

Compromised Pilot Certificate

The compromise of a pilot certificate is much more complicated than the case of a compromised user certificate, since there are only O(10) pilot certificates which are cycled round-robin to run glideinWMS pilots. User jobs will then connect to startd's run by these pilots for executing the user jobs. If a pilot certificate is compromised, then potentially every site and every user of glideinWMS for CMS analysis during the time since the compromise can be affected. The time and effort to determine which, if any, proxies were not compromised might be prohibitive. In this case, it may be more efficient to shut down the entire system, clean up, and restart with un-compromised proxies. However, for the purposes of SSC6, we will not halt glidein CRAB operations or kill pilots. Simply make sure that such information that would be needed to carry out such an operation is obtainable and communication lines are working.

How do you know a pilot proxy was compromised? While this is a good question, for the purposes of SCC6 we will simply be told.

Initial Actions

If a glideinWMS pilot DN is compromised, admins will have to:

  • Remove the particular pilot proxy from the rotation in the glideinWMS frontend and replace it with another of the 50 we have available. (N.B. As of Wednesday August 29, 2012 the additional proxies are not yet registered with the CMS VO.)
  • Ask Factory Ops to kill any running pilots with the banned proxy and remove any queued pilots.
  • Ban the compromised pilot DN at on the condor collector

Detailed Procedures

There are two frontend instances running on under user frontend, instance_v5_4 for general usage and instance_o5_4 for xrootd overflow. These procedures could apply to either frontend.

Pilot certificates are removed from the configuration file frontend.xml in the CMS frontend, in ~/frontstage/instance_[ov]5_4.cfg in the section under security. For example, there is a list of pilot certificates used:

               <proxy absfname="/home/frontend/.globus/x509_pilot05_cms_prio.proxy" security_class="cmsprio"/>
               <proxy absfname="/home/frontend/.globus/x509_pilot06_cms_prio.proxy" security_class="cmsprio"/>
               <proxy absfname="/home/frontend/.globus/x509_pilot07_cms_prio.proxy" security_class="cmsprio"/>
               <proxy absfname="/home/frontend/.globus/x509_pilot08_cms_prio.proxy" security_class="cmsprio"/>
               <proxy absfname="/home/frontend/.globus/x509_pilot09_cms_prio.proxy" security_class="cmsprio"/>
               <proxy absfname="/home/frontend/.globus/x509_pilot10_cms_prio.proxy" security_class="cmsprio"/>

Remove the compromised proxy from the list and replace it with another that is not being used already in this frontend or in any other running frontend on the machine. Other certificates can be found in ~/.globus (but they are not yet registed with the CMS VO).

Reconfigure the frontend:

./frontend_startup reconfig ../instance_v5_4.cfg/frontend.xml

To remove all running and queued pilots with a particular DN, it is necessary to contact the Factory Operators (

Collecting Information

  • find out which sites pilot jobs ran on using this proxy (above) and notify them
  • find out which users had jobs which ran on pilots with a compromised proxy

Detailed Procedures

Given the large number of pilots running at any given time O(10000) and the small number of proxies O(10), every site and every user who ran a job in the glideinWMS analysis system since the time of the compromise of a pilot certificate may have been affected. To make this point, look at every site where pilots are currently running using one certificate:

letts@submit-4 ~$ condor_status -const '(GLIDEIN_X509_GRIDMAP_DNS=?="/DC=org/DC=doegrids/OU=Services/,/DC=org/DC=doegrids/OU=Services/,/DC=org/DC=doegrids/OU=Services/CN=uscmspilot05/")' -l | grep ^GLIDEIN_CMSSite | sort | uniq -c
     20 GLIDEIN_CMSSite = "T1_CH_CERN"
      3 GLIDEIN_CMSSite = "T1_US_FNAL"
      5 GLIDEIN_CMSSite = "T2_BE_IIHE"
     36 GLIDEIN_CMSSite = "T2_BE_UCL"
      5 GLIDEIN_CMSSite = "T2_BR_SPRACE"
      4 GLIDEIN_CMSSite = "T2_BR_UERJ"
     11 GLIDEIN_CMSSite = "T2_CH_CERN"
      2 GLIDEIN_CMSSite = "T2_CH_CSCS"
     39 GLIDEIN_CMSSite = "T2_DE_DESY"
      6 GLIDEIN_CMSSite = "T2_DE_RWTH"
      3 GLIDEIN_CMSSite = "T2_ES_IFCA"
     30 GLIDEIN_CMSSite = "T2_FR_GRIF_LLR"
      4 GLIDEIN_CMSSite = "T2_HU_Budapest"
     37 GLIDEIN_CMSSite = "T2_IT_Bari"
     67 GLIDEIN_CMSSite = "T2_IT_Legnaro"
      9 GLIDEIN_CMSSite = "T2_IT_Pisa"
     18 GLIDEIN_CMSSite = "T2_RU_JINR"
      2 GLIDEIN_CMSSite = "T2_UA_KIPT"
      8 GLIDEIN_CMSSite = "T2_UK_London_Brunel"
      7 GLIDEIN_CMSSite = "T2_UK_London_IC"
     18 GLIDEIN_CMSSite = "T2_UK_SGrid_RALPP"
      1 GLIDEIN_CMSSite = "T2_US_Caltech"
    130 GLIDEIN_CMSSite = "T2_US_Florida"
     13 GLIDEIN_CMSSite = "T2_US_MIT"
     26 GLIDEIN_CMSSite = "T2_US_Nebraska"
      3 GLIDEIN_CMSSite = "T2_US_Purdue"
     41 GLIDEIN_CMSSite = "T2_US_UCSD"
     26 GLIDEIN_CMSSite = "T2_US_Wisconsin"
     64 GLIDEIN_CMSSite = "T3_US_Colorado"
     50 GLIDEIN_CMSSite = "T3_US_Omaha"
     10 GLIDEIN_CMSSite = "T3_US_OSU"
      1 GLIDEIN_CMSSite = "T3_US_TTU"
      7 GLIDEIN_CMSSite = "T3_US_UMD"
This is 33 out of 39 sites running glideins at this time. Over the course of a few hours, this would quickly encompass all sites. Therefore, it is likely that every site running a glidein since the time of the compromise has been affected.

Other Actions

  • Notify the sites where jobs ran with pilots with a compromised credential (effectively all sites).
  • Report the results to CMS Security Contacts (Ian and Mine, and the cms-comp-security mailing list)

General Observation

Note that if a compromise is thought to spread from pilot to user DN and vice-versa, the entire system could be considered compromised on short order, given that user tasks have of order O(1000) jobs and there are only 10 pilot proxies. The probability that any task of 1000 jobs that have already run or started have avoided using pilot with a particular pilot proxy is very very small (1.7 x 10^-46). Therefore, in case of this kind of attack, there may be nothing to do other than holding all user jobs, removing all running and queued pilots, banning the compromised pilot certificates as above, and starting over. (What about compromised user proxies? When would it be safe to let user jobs run again?)

-- JamesLetts - 2012/08/29

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Topic revision: r5 - 2012/08/29 - 23:45:28 - JamesLetts
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