CVE-2020-3549

Cisco Firepower Management Center Software and Firepower Threat Defense Software sftunnel Pass the Hash Vulnerability

HIGH
8.1
CVSS Score
Published: October 21, 2020 at 06:35 PM UTC
Updated: August 11, 2026 at 07:37 PM UTC
3 products affected across 1 vendorSecure Firewall Threat DefenseSecure Firewall Management CenterFirepower Management Center

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Severity
HIGH8.1
Exploit prediction
EPSS 1.0%
SSVC
No known exploit

Description

A vulnerability in the sftunnel functionality of Cisco Firepower Management Center (FMC) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to obtain the device registration hash. The vulnerability is due to insufficient sftunnel negotiation protection during initial device registration. An attacker in a man-in-the-middle position could exploit this vulnerability by intercepting a specific flow of the sftunnel communication between an FMC device and an FTD device. A successful exploit could allow the attacker to decrypt and modify the sftunnel communication between FMC and FTD devices, allowing the attacker to modify configuration data sent from an FMC device to an FTD device or alert data sent from an FTD device to an FMC device.

Affected

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

v < 6.6.1
Affected range stops below 6.6.1, so it looks safe — our inference, not a vendor statement

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 automatableTotal impact

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

CVSS

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

Quick Info

StatusMODIFIED
CWE
CWE-326

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