dbcve.org
Telepresence Video Communication ServerApplication · Cisco

CVE-2024-20492

MEDIUM · 6.7 CVSS v3.1 Published 2024-10-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in the restricted shell of Cisco Expressway Series could allow an authenticated, local attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. To exploit this vulnerability, the attacker must have Administrator-level credentials with read-write privileges on an affected device. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a series of crafted CLI commands. A successful exploit could allow the attacker to escape the restricted shell and gain root privileges on the underlying operating system of the affected device. Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a command injection vulnerability in the restricted shell of Cisco Expressway Series (both Expressway-C and Expressway-E devices). An authenticated attacker with Administrator-level read-write credentials can submit crafted CLI commands that bypass input validation, allowing escape from the restricted shell to execute arbitrary commands as root on the underlying operating system.

MitigationApply the vendor patch when available. Until then, strictly limit Administrator-level account access and monitor CLI activity for signs of shell escape attempts.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Telepresence Video Communication ServerApplication
Affected:= x8.1= x8.1.1= x8.1.2= x8.2= x8.2.1= x8.2.2= x8.5= x8.5.1= x8.5.2= x8.5.3= x8.6= x8.6.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the product as Cisco Expressway Series
    Log into the CLI and run 'xCommand SystemUnitInfo' or check the login banner for 'Expressway' or 'Cisco Telepresence Video Communication Server' branding
    Affected if The device is not a Cisco Expressway Series or Telepresence Video Communication Server, then this CVE does not apply
  2. Check the installed software version
    Run the CLI command 'xCommand SystemUnitInfo' and locate the 'Software version' field. Compare the version number against the affected range: x8.1, x8.1.1, x8.1.2, x8.2, x8.2.1, x8.2.2, x8.5, x8.5.1, x8.5.2, x8.5.3, x8.6, x8.6.1
    Affected if The installed version matches one of the listed versions exactly, then the system is vulnerable
  3. Verify Administrator-level read-write accounts exist
    Run the CLI command 'xCommand UserList' to list all configured users. Look for accounts with 'Administrator' role and 'ReadWrite' access level
    Affected if At least one user account with Administrator role and ReadWrite access exists on the system, the exploitation precondition is present; even if the version is affected, the flaw cannot be exploited without these credentials

The system is affected by CVE-2024-20492 if it is a Cisco Expressway Series device running a version between x8.1 and x8.6.1 inclusive AND has at least one Administrator-level read-write account configured.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch when available. Until then, strictly limit Administrator-level account access and monitor CLI activity for signs of shell escape attempts.

Fix this in Telepresence Video Communication Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-20492 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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