2011ArubaNetworksInc.

FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
SupportAdvisory:ArubaOSDefaultCertificateExpirationIssuedFebruary14,2011UpdatedApril8,2011Thisdocument,includingtheinformationitcontainsandtheprogramsmadeavailablethroughthelinksthatitincludes,isprovidedtoyouonan"asis"basis.
ARUBAANDITSSUPPLIERSDONOTWARRANTTHATSUCHINFORMATIONORTHEFUNCTIONSCONTAINEDINSUCHPROGRAMSWILLMEETYOURREQUIREMENTSORTHATTHEOPERATIONOFTHEPROGRAMSWILLBEUNINTERRUPTEDORERROR-FREE.
THEINFORMATIONANDPROGRAMSAREPROVIDEDTOYOUWITHNOWARRANTYOFANYKIND,EXPRESSORIMPLIED,INCLUDINGWITHOUTLIMITATION,ANYIMPLIEDWARRANTIESOFMERCHANTABILITY,FITNESSFORAPARTICULARPURPOSEANDNONINFRINGEMENT.
INNOEVENTWILLARUBA,ITSSUPPLIERS,ORANYONEELSEWHOHASBEENINVOLVEDINTHECREATION,PRODUCTION,ORDELIVERYOFTHEINFORMATIONORPROGRAMSBELIABLEFORANYDIRECT,INDIRECT,INCIDENTALORCONSEQUENTIALDAMAGES,INCLUDINGWITHOUTLIMITATION,LOSTPROFITSORLOSTDATA,THATMAYARISEOUTOFYOURUSEOFORFAILURETOUSETHEINFORMATIONORPROGRAMS,EVENIFARUBAORSUCHOTHERENTITIESHAVEBEENADVISEDOFTHEPOSSIBILITYOFSUCHDAMAGES.
THEFOREGOINGSHALLNOTBEDEEMEDTOPRECLUDEANYLIABILITYWHICH,UNDERAPPLICABLEPRODUCTSLIABILITYLAW,CANNOTBEPRECLUDEDBYCONTRACT.
ThisdocumentisbeingprovidedtoyoupursuanttotheprovisionsofyourapplicablesoftwarelicenseagreementwithAruba,andtheinformationandprogramsmaybeusedonlypursuanttothetermsandconditionsofsuchagreement.
ThisArubaSecurityAdvisorconstitutesArubaProprietaryInformationandshouldnotbedisseminated,forwardedordisclosed.
2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
SummaryOnJune29,2011thedefaultSSL/TLScertificate"securelogin.
arubanetworks.
com"thatisinstalledonallArubacontrollerswillexpire.
Whilethisdefaultcertificatewasneverintendedforproductionuse,Arubaisawarethatanumberofcustomersareusingthiscertificateinproductionnetworks.
Thesecustomerswillneedtoreplacethecertificate.
Affectedcustomershavetwooptions:1.
Replacethedefaultcertificatewithacertificateissuedbyaninternalcertificateauthorityorapubliccertificateauthority.
Thisoptionisrecommendedandprovidesthegreatestsecurity.
2.
UpgradetheArubaOSimagetoaversionnumberequaltoorgreaterthan3.
3.
3.
10,3.
4.
4.
2,5.
0.
3.
2,6.
0.
1.
1,or6.
1.
0.
0.
Thesesoftwareimagescontainanewdefaultcertificatethatwillreplacetheexpiringcertificate.
Thisoptiondoesnotprovidegoodsecurity,sinceallArubacustomershaveaccesstothesamecertificateandimpersonationattacksarepossible.
2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
BackgroundTheArubaOSoperatingsystemloadedonallArubaMobilityControllerscontainsapre-loadeddigitalcertificatewiththename"securelogin.
arubanetworks.
com".
Thiscertificatewasissuedbyapubliccertificateauthority(CA)thatistrustedbymostbrowsersandoperatingsystems.
Bydefaultthecertificateisusedforthecontroller'smanagementinterface(WebUI),captiveportal,andEAPtermination.
Thiscertificateisintendedforquicklysettinguplabnetworks,demonstrations,andproof-of-conceptdeployments.
Asstatedintheuserguide,thedefaultcertificateisnotintendedforproductiondeployment,sinceeveryArubacontrollercontainsthesamecertificateandthisenablesimpersonationattacks.
Thefollowingtextsummarizestherisks:CaptivePortal:Anattackerimpersonatingacaptiveportalloginscreenmaybeabletoobtaintheusernameandpasswordofauthorizedusersonthesystem.
Ifcaptiveportalisusedonlyforguestaccess,thismaynotbedeemedaserioussecurityrisk.
Ifcaptiveportalisusedtoauthenticateinternalusers,thisattackcouldcausemoreseriousdamage.
AdministrativeWebUI:Tocarryoutanimpersonationattackagainstthecontroller'sadministrativeWebUI,theattackerwouldneedtointercepttrafficbetweenasystemadministrator'scomputerandthecontroller.
Thiswouldtypicallyrequireaninsiderattack,assumingadministrativeaccessisblockedfrompublicnetworks.
Theriskisseriousinthiscase,sinceasuccessfulattackwouldallowanunauthorizedpersontoobtainadministrativecredentialsfortheArubacontroller.
TheWebUIcertificateshouldalwaysbereplaced,evenifwithaself-signedcertificatethateachsystemadministratormustexplicitlytrust.
802.
1XEAPTermination:Thisistheriskiestuseofthedefaultcertificate,becauseanimpersonationattackmaybecarriedoutoverawirelessnetwork,andasuccessfulattackmayrevealusernamesandpasswordhashes(providingmaterialforanofflinepasswordcrackingattempt)orallowtheattackertogetauserconnectedtoahostilenetworkwhiletheuserthinksheorsheisconnectedtoatrustednetwork.
Thedefaultcertificateshouldneverbeusedfor802.
1X.
Arubaisawarethatsomecustomersdousethedefaultcertificateinproduction,typicallyforsecuringthecaptiveportalloginscreeninguestnetworkswhereensuringtheidentityofthecontrollerisnotanimportantsecurityconsideration.
Thedefaultcertificatewasvalidforfiveyears,andwillexpireonJune29,2011.
Ifthenetworkadministratordoesnotreplacethecertificate,thefollowingwilloccur:1.
UsersconnectingtocaptiveportalorWebUIpageswillreceiveabrowserwarningshowingthattheservercertificatehasexpired.
Usersmaybypassthewarning(withvaryingdegreesofdifficultydependingonthebrowser)andcontinueontousethesystemnormally.
2.
IfEAPterminationhasbeenenabledfor802.
1X,andthedefaultcertificateisbeingusedastheservercertificate,manyclientoperatingsystemswillrefusetocontinuetheauthenticationprocess.
Thiswillresultinanapparentnetworkoutagefortheseusers.
Clientoperatingsystemsmayormaynotdisplayawarningmessagetotheuser.
2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
Thisdocumentoutlinestheproceduresneededtoupdatethedefaultcertificate,inorderofpreference:Option1:InstallauniqueservercertificateOption2:UpgradeArubaOS2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
Option1:InstallaUniqueServerCertificateThisistherecommendedapproachsinceitprovidesthebestsecurity.
Inthisapproach,thedefaultcertificatewillremainonthecontroller,butyouwillloadoneormorenewcertificatesandthenconfigurethesystemtousethenewcertificate(s).
Ifyourorganizationoperatesaninternalcertificateauthority(CA)andallclientsthatwillusethesystemalreadytrusttheinternalCA,youmayusetheinternalCAtoissueanewcertificatetothecontroller.
Thisoptionisrecommendedfor802.
1XEAPterminationandWebUIadministrativeaccesstothecontroller.
Itcanalsobeusedforcaptiveportalaslongasthegeneralpublicwillnotbeaccessingthesystem(sincetheinternalCAwillnotbetrusted,thegeneralpublicwouldreceivebrowserwarnings.
)Ifpresentingacaptiveportalpagetocomputersownedbythegeneralpublic,acertificateissuedbyapublicCA(VeriSign,GeoTrust,Comodo,etc.
)shouldbeusedsothatbrowserwarningsarenotgenerated.
YoumaychoosetouseacertificateissuedbyapublicCAforWebUIadministrativeaccesstothecontrollerandfor802.
1XEAPterminationaswell,butuseofapublicCAinsteadofaninternalCAprovidesnobenefitinthosecases.
Beforerequestingacertificate,decidewhetheryouneeda1024-bitkey,2048-bitkey,or4096-bitkey.
NotethatmanypublicCAsnolongerissuecertificateswith1024-bitkeys.
IfyouarerunningArubaOS6.
1orgreater,youmayuseacertificatewitha2048-bitkeyforanypurpose.
Youmayuseacertificatewitha4096-bitkeyonlyforcaptiveportalandWebUI.
ForWebUIorcaptiveportal,performanceisthegreatestwithsmallerkeysizes,butsecurityisslightlyreduced.
Tomaximizecompatibility,alwaysuseRSAunlessyouhaveaspecificreasontouseECC.
Ifyouarerunninganyreleasepriorto6.
1,youmayuseacertificatewitha2048-bitor4096-bitkeyonlyforcaptiveportalandWebUI.
802.
1XEAPterminationsupportsonly1024-bitkeys.
ForWebUIorcaptiveportal,performanceisthegreatestwithsmallerkeysizes,butsecurityisslightlyreduced.
Thefollowinginstructionsshouldbefollowedtoobtainandinstallaservercertificate.
1.
GenerateaCertificateSigningRequest(CSR)fromthecontrollerbynavigatingtoConfigurationManagementCertificatesCSR.
Filloutthenecessaryfields.
Afterclicking"GenerateNew",thecontrollerwillgenerateaprivatekey,whichremainslockedinsidethecontroller,andabase64-encodedCSR.
TheCSRcontainsallthedetailsneededforyourCAtoissuethecertificate.
TheCommonName(CN)fieldshouldcontainthefullURLthatwebbrowserswillnavigatetoinordertoreachthecontroller'sembeddedwebserver.
TakecaretofillouttheCommonNamefieldcorrectlyaccordingtothepurposeofthecertificate:a.
Forcaptiveportal,thesystemwillautomaticallyissueHTTPredirectsandspoofDNSresponsestothecaptiveportalclientsothatthebrowserappearstobeconnectingtothecorrectDNSnamethatmatchesthecertificatecommonname.
Thisistoensurethatbrowserwarningsarenotgenerated.
Ifthecertificateisonlybeingusedforcaptiveportal,thenameintheCNfieldisunimportant–butmakesureitfallswithin2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
yourdomainnamesothatapublicCAwillcorrectlyauthorizeownershipofthecertificate.
b.
ForWebUI,theCNfieldshouldmatchtheaddressyouusetomanagethecontroller.
ThiscanbeanIPaddressoraFullyQualifiedDomainName(FQDN).
c.
For802.
1XEAPTermination,theCNfieldisnotmatchedbytheclientagainstanyotherparameter.
ItissuggestedthatyouchooseaFQDNthatisownedbyyourorganization.
2.
Clickon"ViewCurrent".
Copythebase64textshown,andpastethisintothecertificaterequestwindowprovidedbyyourcertificateauthority.
2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
3.
Onceyouhaveobtainedthecertificate,navigatetoConfigurationManagementCertificatesUploadanduploadthecertificatetothecontroller.
ThecertificatewillmostlikelybeprovidedtoyouinPEMorDERformat–ifyouarenotsurewhichformatitisin,tryPEMfirstandifanerrormessageresults,tryDER.
APEMformatcertificatewillbebase64-encodedandwillbeginwiththetext"-----BEGINCERTIFICATE-----".
4.
Ifyouwanttousethenewcertificateforcaptiveportal,navigatetoConfigurationManagementGeneralandchangetheCaptivePortalServerCertificate.
IfyouwanttousethenewcertificateforWebUI,configurationisfoundonthesamescreenunder"WebUIManagementAuthenticationMethod".
5.
IfyouwanttousethenewcertificateforEAPTermination,navigatetoConfigurationSecurityAuthenticationL2Authentication802.
1XAuthentication2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
ProfileAdvancedandchangetheservercertificateforallactive802.
1XauthenticationprofilesthatuseEAPTermination.
2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
Option2:UpgradeArubaOSArubahasobtainedanewcertificatelabeled"securelogin.
arubanetworks.
com"fromapublicCAthatreplacestheolddefaultcertificate.
ThenewcertificatehasanexpirationdateofNovember21,2013.
ThiscertificateisincludedaspartofthefollowingArubaOSsoftwarereleases:6.
1beginningwithrelease6.
1.
0.
06.
0beginningwithrelease6.
0.
1.
15.
0beginningwithrelease5.
0.
3.
23.
4beginningwithrelease3.
4.
4.
23.
3beginningwithrelease3.
3.
3.
10AllotherArubaOSreleasesdatedlaterthanJune1,2011Afterupgradingtooneoftheabovelistedreleases,nofurtheractionisrequiredtoenablethecertificate.
Ifthesystemwaspreviouslyconfiguredtousethedefaultcertificate,itwillautomaticallyusethenewlyupdatedcertificate.
Whilethisoptionprovidesthesamelevelofsecuritygivenbythepreviousdefaultcertificate,itisnotagoodoptionwhereanysecurityrequirementsexist.
SSL/TLSsecurityisprovidedbythecertificate'sprivatekeybeingkeptsecret.
Ifthecertificate'sprivatekeybecomesknown,itispossibleforanattackertoimpersonateanyserverorwebsiteusingthatcertificatewithouttheknowledgeoftheenduser.
BecausethesamecertificateandprivatekeyareinstalledonallArubacontrollers,anattackerneedonlyreverseengineerasinglesoftwareimagetoobtaintheprivatekey.
Whilethisprocessisnon-trivial,itiscertainlynotbeyondthemeansofaskilledanddeterminedattacker.
ItisalsopossibleforanattackertosimplypurchaseanduseanArubacontrollerforthepurposeofconductinganimpersonationattack.
2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
FAQQ:WhathappensifIhaveconfigured802.
1Xdevicesinmynetworktoonlytrustthe"securelogin.
arubanetworks.
com"certificate,ortoonlytrusttheEquifaxSecureCertificateAuthorityA:Thesedeviceswillneedtobereconfiguredafterinstallationofanewcertificate.
IftheseareWindowsdevices,UNCHECK"Connecttotheseservers"andUNCHECK"EquifaxSecureCertificateAuthority"intheTrustedRootCertificationAuthorities.
Afterconnectingtothecontrollerwiththenewcertificateinstalled,Windowswillupdatethesesettingsbypromptingtheuser.
Q:IsthecertificatebuiltintotheTPMchipaffectedbythisadvisoryA:No.
AllArubacontrollersthatcontainaTrustedPlatformModule(TPM),includingtheM3,3000series,and600series,containacertificateuniquetothecontrollerthathasbeenprogrammedatthefactory.
Thiscertificateisnotexpiringandisnotaffectedbythisadvisory.
ThiscertificateisusedforMaster-Localauthentication,ControlPlaneSecurity(CPsec),andRAPauthentication.
ItisnotsuitableforuseasanSSLcertificatesinceitwasissuedbyAruba'smanufacturingCA,whichisnottrustedbybrowsers.
Q:WhatcertificateauthoritywasusedtogeneratethenewcertificateWhatchainsdoesitcontain2011ArubaNetworksInc.
FurtherdistributionprohibitedwithoutpriorwrittenconsentfromArubaNetworksInc.
ForArubaCustomers,EmployeesandAuthorizedChannelPartnersOnly.
A:ThenewcertificatewasissuedbyPositiveSSL,andultimatelychainsbackuptoUSERTrust,whichisissuedbyAddTrustExternalCARoot.
DevicesconnectingtothenetworkmusthaveUSERTrustinstalledasatrustedrootCAinorderfortheArubafactorydefaultcertificatetobetrusted.
UnderaWindowssystem,thecertificatechainappearsas