CVE-2021-34761

Cisco Firepower Threat Defense Software CLI Arbitrary File Write Vulnerability

MEDIUM
6
CVSS Score
Published: October 27, 2021 at 06:55 PM UTC
Updated: August 11, 2026 at 07:33 PM UTC
3 products affected across 1 vendorSecure Firewall Threat DefenseFirepower Management Center Virtual ApplianceSourcefire Defense Center

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Severity
MEDIUM6
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-73CWE-668

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