In the delicate world of enterprise video conferencing, device security often flies under the radar. But in 2022, a nasty bug—CVE-2022-20931—surfaced in Cisco TelePresence CE Software used by popular Cisco Touch 10 devices. This vulnerability allowed someone on the same network to “downgrade” the software to an older, insecure version, reintroducing patched vulnerabilities and putting sensitive communications at risk.
Let’s break down how this flaw worked, see how an attacker could exploit it, and learn what you need to do if you still have vulnerable devices on your network.
What Is CVE-2022-20931?
CVE-2022-20931 is a vulnerability in version control logic within Cisco TelePresence CE Software for Cisco Touch 10 devices—a touchscreen controller usually found in meeting spaces. The essence of the bug: The device failed to properly check and restrict the software versions being installed. That meant attackers nearby could load an older, less secure version of the control software and, from there, exploit older vulnerabilities that had already been fixed in newer versions.
Impact:
Grab an Old CE Software Version:
From Cisco’s archives (or previously downloaded versions), the attacker gets an outdated .pkg (package) file.
Gains a New (Old) Playground:
The device, now running out-of-date software, may have known vulnerabilities. The attacker can use published exploits targeting those weaknesses.
!Vulnerability Exploit Chain
*Image: Attack flow from downgrade to full compromise.*
Let’s look at a simplified code example illustrating the lack of version validation in a pseudocode handler:
# Pseudocode for update process (VULNERABLE)
def handle_software_update(pkg_file):
# Extract version from the provided package
new_version = pkg_file.version
# CURRENT VERSION on device
current_version = device.get_installed_version()
# (Vulnerability) No check if 'new_version' < 'current_version'
device.install(pkg_file)
log("Installed version: {}".format(new_version))
*A patched handler would check that new_version >= current_version.*
Real Risk: What an Attacker Can Do
Suppose Cisco patching closed a previous critical bug in version 9.7 but your device is on 9.9. An attacker rolls you back to 9.7. Now, all the public exploits and bugs from 9.7 are back in play.
Cisco’s Official Advisory:
Cisco TelePresence CE Software Vulnerability (CVE-2022-20931)
NIST NVD Entry:
https://nvd.nist.gov/vuln/detail/CVE-2022-20931
Rapid7 Analysis:
Exploit Scenario: A Step-By-Step Demonstration
> Note: This demonstration is a safe, conceptual summary—do not attempt on production devices.
`sh
nmap -p 80,443 10.../24 --open
`sh
curl -k -F "firmware=@ce9.7.pkg" https://10...55/upload
`
Mitigation and Updates
There is no workaround. The only fix is to update your Cisco TelePresence CE Software to a patched version.
Go to Cisco’s official page:
Why Did This Matter?
In the world of security, preventing *downgrade attacks* is crucial. It’s not enough to just patch new code—you must make sure attackers can’t send you *back in time* to where bugs still exist. CVE-2022-20931 was a reminder that:
Conclusion
CVE-2022-20931 was simple, yet dangerous. By failing to prevent downgrades, critical Cisco video conference devices could be easily re-broken. If you run Cisco’s TelePresence or Touch 10s, patch now—and make version control testing part of your regular device maintenance.
For more technical info
- Cisco security advisory
- CVE Details
- Learn about downgrade attacks
Don’t let attackers turn the clock back on your security!
Timeline
Published on: 11/15/2024 15:30:29 UTC