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A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software could allow an… (CVE-2026-20324)

0
Critical
Published: 09/16/2026 (09/16/2026, 21:32:45 UTC)
Source: GCVE Database

Description

CVE-2026-20324 is a critical vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software. It allows an authenticated remote attacker with valid user credentials to execute arbitrary commands as root by exploiting improper file write permissions. The attacker can hijack or act as a registered sftunnel peer to write and execute malicious files with root privileges on the affected device.

CVSS v3.1

Score 9.9critical

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/17/2026, 02:41:31 UTC

Technical Analysis

This vulnerability arises because a registered sftunnel peer has incorrect permissions that allow writing arbitrary files to any location on the device. An attacker with valid credentials can exploit this by sending a malicious sftunnel command to write a file that is executed with root privileges, leading to full system compromise. Exploitation requires authentication and leverages the sftunnel communication channel within Cisco Secure Firewall Management Center (FMC) Software.

Potential Impact

Successful exploitation results in arbitrary command execution as root, compromising confidentiality, integrity, and availability of the affected system. This can lead to full system takeover by an attacker with valid credentials.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, restrict access to valid user credentials and monitor for unauthorized sftunnel communication. Follow Cisco's official guidance once published.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
GHSA-m3pq-vq89-c8m5
Osv Schema Version
1.4.0
Aliases
["CVE-2026-20324"]
Database Specific Severity
CRITICAL
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6aab49aa55bf5e2cf599290d

Added to database: 09/17/2026, 02:00:10 UTC

Last enriched: 09/17/2026, 02:41:31 UTC

Last updated: 09/17/2026, 04:01:24 UTC

Views: 3

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