Cyber Resilience

CVE-2021-34716

Medium

Published: 18 August 2021

Published
18 August 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.7 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L
EPSS Score 0.0110 78.5th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-34716 is a medium-severity Improper Cleanup on Thrown Exception (CWE-460) vulnerability in Cisco Expressway. Its CVSS base score is 6.7 (Medium).

Operationally, ranked in the top 21.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cisco
expressway
x8.6.0 — x14.1
cisco
telepresence video communication server
x8.6 — x14.0.3

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-755

Provides defined handling (alert and additional actions) for the exceptional condition of audit logging failure.

addresses: CWE-755

Supplies a concrete handling action (safe mode) for exceptional conditions, mitigating risks from improper or absent handling that could allow continued attacks.

addresses: CWE-755

By preparing users for contingency scenarios, the control promotes proper handling of exceptional conditions instead of default or unsafe behaviors.

addresses: CWE-755

An updated contingency plan defines current actions for exceptional conditions, reducing the window for attackers to exploit improper handling leading to system failure.

addresses: CWE-755

Procedures ensure proper handling of exceptional conditions to support effective incident response.

addresses: CWE-755

Incident response testing confirms proper handling of exceptional conditions to limit exploit impact.

addresses: CWE-755

Gives users guidance on incident handling, reducing improper handling of exceptional conditions that could stem from exploited weaknesses.

addresses: CWE-755

Enforces structured response to exceptional conditions so the system cannot remain in an unsafe state.

References