Cisco IP Phone Cleartext Password Storage

`SEC Consult Vulnerability Lab Security Advisory < 20220113-0 >  
=======================================================================  
title: Cleartext Storage of Phone Password  
product: Cisco IP Phone Series 78x1, 88x5, 88x1, 7832,  
8832, 8821 and 3905  
vulnerable version: Firmware <14.1.1,  
Firmware <11.0(6)SR2 (device model 8821),  
Firmware <9.4(1)SR5 (device model 3905)  
fixed version: Firmware 14.1.1, 11.0(6)SR2, 9.4(1)SR5  
CVE number: CVE-2022-20660  
impact: Medium  
homepage: https://www.cisco.com  
found: 2021-04-15  
by: Gerhard Hechenberger (Office Vienna)  
Steffen Robertz (Office Vienna)  
SEC Consult Vulnerability Lab  
  
An integrated part of SEC Consult, an Atos company  
Europe | Asia | North America  
  
https://www.sec-consult.com  
  
=======================================================================  
  
Vendor description:  
-------------------  
"The Cisco® IP Phone 7800 Series is a cost-effective, high-fidelity voice  
communications portfolio designed to improve your organization’s people-centric  
communications, while reducing your operating costs. It combines an attractive  
new ergonomic design with “always-on” reliability and secure encrypted  
communications. The Cisco® IP Phone 7800 Series delivers advanced IP Telephony  
features and crystal clear wideband audio performance to deliver an  
easy-to-use, full-featured voice communications experience on Cisco on-premises  
and hosted infrastructure platforms and third party hosted call control."  
  
Source: https://www.cisco.com/c/en/us/products/collateral/collaboration-endpoints/unified-ip-phone-7800-series/data-sheet-c78-729488.html  
  
  
Business recommendation:  
------------------------  
SEC Consult recommends to update the devices to the newest firmware listed  
below, where, according to the vendor, the documented issue is fixed.  
  
We want to thank Cisco for the very professional response and great coordination.  
  
  
Vulnerability overview/description:  
-----------------------------------  
1) Cleartext Storage of Phone Password  
The phone is storing the "phone password", which is needed to access its  
administrative settings, in cleartext (in multiple locations) in the flash  
memory.  
  
Because the password is not hashed using a suitable cryptographic hash function  
and the storage is unencrypted, a physical attacker can easily recover the  
password and reuse it on other phones, if they are not configured to use unique  
administrative passwords.  
  
  
Proof of concept:  
-----------------  
1) Cleartext Storage of Phone Password  
Steps to take:  
- Configure a phone password via the TFTP XML provisioning feature.  
- Desoldering the memory and reading its content.  
- Analyzing the memory content. As example, the Linux command 'strings' can be  
used below to show the identified password in cleartext in the dumped data.  
----------------------------------------  
$ strings nand.dump | grep phonePassword  
phonePassword>sectest</,x  
phonePassword>sectest</,x  
phonePassword>sectest</,x  
phonePassword>sectest</,x  
----------------------------------------  
  
  
Vulnerable / tested versions:  
-----------------------------  
The following firmware/device has been tested:  
* Cisco IP Phone 7821: Firmware version 12.8.1-0001-455  
  
The vendor confirmed that the following devices are affected:  
* Cisco IP Phone 78x1 all releases before firmware version 14.1.1  
* Cisco IP Phone 88x5 all releases before firmware version 14.1.1  
* Cisco IP Phone 88x1 all releases before firmware version 14.1.1  
* Cisco IP Phone 7832 all releases before firmware version 14.1.1  
* Cisco IP Phone 8832 all releases before firmware version 14.1.1  
* Cisco IP Phone 8821 all releases before firmware version 11.0(6)SR2  
* Cisco IP Phone 3905 all releases before firmware version 9.4(1)SR5  
  
  
Vendor contact timeline:  
------------------------  
2021-05-19: Contacting vendor through [email protected]. Set preliminary release  
date to 2021-08-07. Received PSIRT case number from Cisco employee.  
2021-05-20: Cisco states that the finding has been shared with the development  
team and is currently being analyzed.  
2021-06-30: Cisco confirms affected phone models and communicates expected  
dates for fixed firmware releases.  
2021-07-07: New estimated release date was set to 2022-01-31.  
2021-12-27: Cisco informs about the fix and the publishing date 2022-01-12 for  
their advisory  
2022-01-13: Coordinated release of the security advisory.  
  
  
  
Solution:  
---------  
Update the firmware of the affected devices to the latest available version.  
See the vendor's security advisory for further information:  
  
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ip-phone-info-disc-fRdJfOxA  
  
  
Workaround:  
-----------  
For immediate mitigation, ensure that phones are configured to use unique  
administrative passwords.  
  
  
Advisory URL:  
-------------  
https://sec-consult.com/vulnerability-lab/  
  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
SEC Consult Vulnerability Lab  
  
SEC Consult, an Atos company  
Europe | Asia | North America  
  
About SEC Consult Vulnerability Lab  
The SEC Consult Vulnerability Lab is an integrated part of SEC Consult, an  
Atos company. It ensures the continued knowledge gain of SEC Consult in the  
field of network and application security to stay ahead of the attacker. The  
SEC Consult Vulnerability Lab supports high-quality penetration testing and  
the evaluation of new offensive and defensive technologies for our customers.  
Hence our customers obtain the most current information about vulnerabilities  
and valid recommendation about the risk profile of new technologies.  
  
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EOF Gerhard Hechenberger, Steffen Robertz / @2022  
  
  
`