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Vulnerability record · CVE-2021-34716 · published 18 August 2021

CVE-2021-34716: Cisco expressway vulnerability

Cisco · Expressway

A vulnerability in the web-based management interface of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to execute arbitrary code on the underlying operating system as the root user. This vulnerability is due to incorrect handling of certain crafted software images that are uploaded to the affected device. An attacker could exploit this vulnerability by authenticating to the system as an administrative user and then uploading specific crafted software images to the affected device. A successful exploit could allow the attacker to execute arbitrary code on the underlying operating system as the root user.

7.2 CVSS 3.1 High EPSS 2.4% · top 16.7% CWE-460 · CWE-460CWE-755 · CWE-755
7.2CVSS 3.1 base score, v2 9.0
2.4%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A vulnerability in the web-based management interface of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to execute arbitrary code on the underlying operating system as the root user. This vulnerability is due to incorrect handling of certain crafted software images that are uploaded to the affected device. An attacker could exploit this vulnerability by authenticating to the system as an administrative user and then uploading specific crafted software images to the affected device. A successful exploit could allow the attacker to execute arbitrary code on the underlying operating system as the root user.

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

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewrce-QPynNCjh PatchVendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewrce-QPynNCjh PatchVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-34716), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.