CVE-2021-34716Known exploitationNetwork attack vector

Administrator-authenticated root code execution via crafted image upload

Published Aug 18, 2021 · Updated Nov 7, 2024

Code execution in Cisco TelePresence VCS Expressway X8.6 through X14.0.2 allows remote authenticated users to run code as root. The web management interface incorrectly handles a crafted software image during an administrative upload and passes its contents into privileged execution. Administrative credentials and management-plane access are required; successful exploitation grants control of the underlying operating system.

CVSS severity6.7
Medium
EPSS probability2.40%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code execution in Cisco TelePresence VCS Expressway X8.6 through X14.0.2 allows remote authenticated users to run code as root. The web management interface incorrectly handles a crafted software image during an administrative upload and passes its contents into privileged execution. Administrative credentials and management-plane access are required; successful exploitation grants control of the underlying operating system.

The record

CVE
CVE-2021-34716
Published
Aug 18, 2021
Updated
Nov 7, 2024
Vendor
ClamAV
Product
Cisco TelePresence Video Communication Server (VCS) Expressway
Classifications
CWE-460, CWE-755, T1068
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ClamAV · Cisco TelePresence Video Communication Server (VCS) Expresswayversion=n/a

Published CVSS scores

6.7Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L/E:X/RL:X/RC:X
9.0NISTAV:N/AC:L/Au:S/C:C/I:C/A:C
7.2NISTCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-460Improper Cleanup on Thrown Exception
CWE-755Improper Handling of Exceptional Conditions
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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