CVE-2023-20006

highpriority · track · 30EPSS 0.009 · 60 %ileDEEUNLRUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.93% (60th) EPSS

CVSS 7.5 · high

Is it mine?

65 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A vulnerability in the hardware-based SSL/TLS cryptography functionality of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to an implementation error within the cryptographic functions for SSL/TLS traffic processing when they are offloaded to the hardware. An attacker could exploit this vulnerability by sending a crafted stream of SSL/TLS traffic to an affected device. A successful exploit could allow the attacker to cause an unexpected error in the hardware-based cryptography engine, which could cause the device to reload.

remediations

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

A vendor fix is available.

FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.14 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.18 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.19 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.27 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.9 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.17.1.30 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.17.1.33 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2.5 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2.7 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2.8 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.3 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.3.39 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.3.46 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.3.53 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.19.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.19.1.12 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.19.1.18 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.19.1.5 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.19.1.9 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 7.2.1 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 7.2.2 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 7.2.3 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 7.2.4 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 7.2.4.1 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 7.2.5 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 7.3.0 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 7.3.1 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 7.3.1.1 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 7.3.1.2 when installed on Cisco Firepower 2100 Seriescisco_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

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

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-681USprimaryCWE-20USCWE-681US

affected products (65)

Products and version ranges known to be affected.

Cisco ASA (Adaptive Security Appliance) 9.16.4all versionscert_bundDEcpe:/h:cisco:adaptive_security_appliance:9.16.4
Cisco ASA (Adaptive Security Appliance) 9.18.2all versionscert_bundDEcpe:/h:cisco:adaptive_security_appliance:virtual__9.18.2
Cisco ASA (Adaptive Security Appliance) 9.18.2.5all versionscert_bundDEcpe:/h:cisco:adaptive_security_appliance:9.18.2.5
Cisco Firepower FTD 7.2.1all versionscert_bundDEcpe:/a:cisco:firepower:ftd_7.2.1
Cisco Firepower FTD 7.2.2all versionscert_bundDEcpe:/a:cisco:firepower:ftd_7.2.2
Cisco Firepower FTD 7.2.3all versionscert_bundDEcpe:/a:cisco:firepower:ftd_7.2.3
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.14 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.18 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.19 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.27 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.4.9 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.17.1.30 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.17.1.33 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2.5 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2.7 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.2.8 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.3 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.3.39 when installed on Cisco Firepower 2100 Seriesall versionscisco_csafUS

showing 20 of 65

advisories (3)

Vendor and ecosystem advisories describing this.

NCSC-2024-0233Kwetsbaarheden verholpen in Cisco productenNL2024-05-23csaf · ncsc_nlNL
Cisco heeft kwetsbaarheden verholpen in ASA, Firepower en Snort.
WID-SEC-W-2023-1397Cisco ASA (Adaptive Security Appliance): Schwachstelle ermöglicht Denial of ServiceDeutsch2023-06-08csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Cisco ASA (Adaptive Security Appliance) und Cisco Firepower ausnutzen, um einen Denial of Service Angriff durchzuführen.
cisco-sa-asaftd-ssl-dos-uu7mV5p6Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software for Firepower 2100 Series Appliances SSL/TLS Denial of Service Vulnerability2023-06-07csaf · cisco_csafUS
A vulnerability in the hardware-based SSL/TLS cryptography functionality of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to an implementation error within the cryptographic functions for SSL/TLS traffic processing when they are offloaded to the hardware. An attacker could exploit this vulnerability by sending a crafted stream of SSL/TLS traffic to an affected device. A successful exploit could allow the attacker to cause an unexpected error in the hardware-based cryptography engine, which could cause the device to reload. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund cisco_csaf ncsc_nl NVD CVE.org MITRE

published 2023-06-28modified 2026-08-11

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+173 more

references (6)

External citations — patches, advisories, analysis.

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