CVE intelligence and bounded remediation

CVE-2021-34761 — Cisco Firepower Management Center Virtual Appliance security vulnerability

Medium CVSS 6.6

A vulnerability in Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to overwrite or append arbitrary data to system files using root-level privileges. The attacker must have administrative credentials on the device. This vulnerability is due to incomplete validation of user input for a specific CLI command. An attacker could exploit this vulnerability by authenticating to the device with administrative privileges and issuing a CLI command with crafted user parameters. A successful exploit could allow the attacker to overwrite or append arbitrary data to system files using root-level privileges.

Severity
Medium
CVSS
6.6 (2.0)
Published
2021-10-27
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-73, CWE-668

Affected products

  • cisco / firepower_management_center_virtual_appliance / 6.2.3
  • cisco / firepower_management_center_virtual_appliance / 6.4.0
  • cisco / firepower_management_center_virtual_appliance / 6.6.1
  • cisco / firepower_management_center_virtual_appliance / 6.7.0
  • cisco / firepower_management_center_virtual_appliance / 7.0.0
  • cisco / firepower_management_center_virtual_appliance / 7.1.0

Showing 6 representative product identities from 16 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Path traversal, unsafe upload, and file handling

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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