CVE-2022-20854Network attack vector

Unauthenticated reboot via failed SSH session flood

Published Nov 10, 2022 · Updated Aug 3, 2024

Denial of service in Cisco FMC and FTD Software allows remote attackers to reboot affected devices via crafted SSH connections. SSH connection processing improperly handles failed session establishment, allowing a high rate of crafted connection attempts to exhaust resources. No authentication is required; SSH is enabled by default on FMC management interfaces but not on FTD data interfaces, and exhaustion reboots the device.

CVSS severity7.5
High
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Cisco FMC and FTD Software allows remote attackers to reboot affected devices via crafted SSH connections. SSH connection processing improperly handles failed session establishment, allowing a high rate of crafted connection attempts to exhaust resources. No authentication is required; SSH is enabled by default on FMC management interfaces but not on FTD data interfaces, and exhaustion reboots the device.

The record

CVE
CVE-2022-20854
Published
Nov 10, 2022
Updated
Aug 3, 2024
Vendor
ClamAV
Product
Cisco Firepower Threat Defense Software
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 10, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=N/A

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Firepower Threat Defense Softwareversion=N/A
ClamAV · Cisco Firepower Management Centerversion=N/A

Published CVSS scores

7.5CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo