CVE-2022-20746

highpriority · track · 30EPSS 0.014 · 72 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.36% (72nd) EPSS

CVSS 7.1 · high

Is it mine?

20 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the TCP proxy functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper handling of TCP flows. An attacker could exploit this vulnerability by sending a crafted stream of TCP traffic through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

8.6

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–8.6

v2.07.1highAV:N/AC:M/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 8.6 · impact 6.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.18.6highAV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU

v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 4

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-476USprimaryCWE-476US

affected products (20)

Products and version ranges known to be affected.

Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)all versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco ASA 5500-X Series Firewallsall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 1000 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 4100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 9000 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Secure Firewall Threat Defense Virtualall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)all versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco ASA 5500-X Series Firewallsall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 1000 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 4100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 9000 Seriesall versionscisco_csafUS
Cisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Secure Firewall Threat Defense Virtualall versionscisco_csafUS
Cisco Cisco Firepower Threat Defense Software≤ n/aenisa_euvdEU
Cisco Systems Inc. Firepower Threat Defense7.0.0 → 7.0.1fstec_bduRU
cisco secure firewall threat defense< 6.4.0.15nvdUScpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
cisco secure firewall threat defense6.5.0 → 6.6.5.2nvdUScpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
cisco secure firewall threat defense7.0.0 → 7.0.2nvdUScpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
cisco secure firewall threat defense= 7.1.0nvdUScpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-ftd-tcp-dos-kM9SHhOuCisco Firepower Threat Defense Software TCP Proxy Denial of Service Vulnerability2022-04-27csaf · cisco_csafUS
A vulnerability in the TCP proxy functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper handling of TCP flows. An attacker could exploit this vulnerability by sending a crafted stream of TCP traffic through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-tcp-dos-kM9SHhOu ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-tcp-dos-kM9SHhOu"] This advisory is part of the April 2022 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see Cisco Event Response: April 2022 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74836"].

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf nvd NVD CVE.org MITRE

published 2022-05-03modified 2026-08-11

related (8,786)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-21525US	—OT critical	4.87% (92nd)	KEV	2026-02-10
Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker to deny service locally.
CVE-2010-0425US	high10.0	94.2% (100th)	Exploit	2010-03-05
modules/arch/win32/mod_isapi.c in mod_isapi in the Apache HTTP Server 2.0.37 through 2.0.63, 2.2.0 through 2.2.14, and 2.3.x before 2.3.7, when running on Windows, does not ensure…
CVE-2012-0779US	high9.3	87.1% (100th)	Exploit	2012-05-04
Adobe Flash Player before 10.3.183.19 and 11.x before 11.2.202.235 on Windows, Mac OS X, and Linux; before 11.1.111.9 on Android 2.x and 3.x; and before 11.1.115.8 on Android 4.x a…
CVE-2012-5896US	high10.0	68.7% (99th)	Exploit	2012-11-17
The Annotation Objects Extension ActiveX control in AnnotateX.dll in Quest InTrust 10.4.0.853 and earlier does not properly implement the Add method, which allows remote attackers…
CVE-2003-0772US	high7.5	84.9% (100th)	Exploit	2003-09-22
Multiple buffer overflows in WS_FTP 3 and 4 allow remote authenticated users to cause a denial of service and possibly execute arbitrary code via long (1) APPE (append) or (2) STAT…

+8781 more

references (6)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan