CyberSecBulletin
CVE-2022-20814NVD status: Analyzed

Cisco TelePresence Video Communication Server…: Improper Certificate Validation

Published Updated By the CyberSecBulletin desk

CVE-2022-20814 is a high-severity improper certificate validation vulnerability in Cisco TelePresence Video Communication Server (VCS) Expressway from Cisco, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco TelePresence Video Communication Server (VCS) Expressway versions: X8.11.2; X8.6; X8.11.3, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.91% chance of exploitation within 30 days, higher than 61% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update telepresence_video_communication_server to 14.2 or a later version.
  2. Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco TelePresence Video Communication Server (VCS) ExpresswayX8.11.2; X8.6; X8.11.3; X8.2.2; X8.8.3; X8.11.0; X12.5.2; X8.1.1; and 32 more rangesNot stated
Ciscotelepresence_video_communication_serverbefore 14.214.2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (cisco.com).

Official description

A vulnerability in the certificate validation of Cisco Expressway-C and Cisco TelePresence VCS could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data.  The vulnerability is due to a lack of validation of the SSL server certificate that an affected device receives when it establishes a connection to a Cisco Unified Communications Manager device. An attacker could exploit this vulnerability by using a man-in-the-middle technique to intercept the traffic between the devices, and then using a self-signed certificate to impersonate the endpoint. A successful exploit could allow the attacker to view the intercepted traffic in clear text or alter the contents of the traffic. Note: Cisco Expressway-E is not affected by this vulnerability.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

How developers prevent this class of flaw

  • Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
  • If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.

More Improper Certificate Validation vulnerabilities (CWE-295)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco TelePresence Video Communication Server (VCS) Expressway

All Cisco TelePresence Video Communication Server (VCS) Expressway vulnerabilities

Recent Improper Certificate Validation vulnerabilities

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