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TI-2023-06751 Aliases CVE-2023-20042GHSA-2c63-fqw2-3fhm

A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance…

Priority LOW 39CWE-404Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-404.

Summary

A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an implementation error within the SSL/TLS session handling process that can prevent the release of a session handler under specific conditions. An attacker could exploit this vulnerability by sending crafted SSL/TLS traffic to an affected device, increasing the probability of session handler leaks. A successful exploit could allow the attacker to eventually deplete the available session handler pool, preventing new sessions from being established and causing a DoS condition.

Why it matters now

EPSS 0.00903 59th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco Adaptive Security Appliance (ASA) Software9.16.1; 9.16.1.28; 9.16.2; 9.16.2.3; 9.16.2.7; 9.16.2.11; 9.16.2.13; 9.16.2.14; 9.16.3; 9.16.3.3; 9.16.3.14; 9.16.3.15; 9.16.3.19; 9.16.3.23; 9.16.4; 9.16.4.9; 9.17.1; 9.17.1.7; 9.17.1.9; 9.17.1.10; 9.17.1.11; 9.17.1.13; 9.17.1.15; 9.17.1.20; 9.18.1; 9.18.1.3; 9.18.2; 9.18.2.5; 9.18.2.7; 9.19.1—No fix listedCNA
CiscoCisco Firepower Threat Defense Software7.0.0; 7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.0.2.1; 7.0.3; 7.0.4; 7.0.5; 7.1.0; 7.1.0.1; 7.1.0.2; 7.1.0.3; 7.2.0; 7.2.0.1; 7.2.1; 7.2.2; 7.2.3; 7.3.0; 7.3.1; 7.3.1.1—No fix listedCNA
  • Cisco Adaptive Security Appliance (ASA) Software VendorCisco Affected 9.16.1; 9.16.1.28; 9.16.2; 9.16.2.3; 9.16.2.7; 9.16.2.11; 9.16.2.13; 9.16.2.14; 9.16.3; 9.16.3.3; 9.16.3.14; 9.16.3.15; 9.16.3.19; 9.16.3.23; 9.16.4; 9.16.4.9; 9.17.1; 9.17.1.7; 9.17.1.9; 9.17.1.10; 9.17.1.11; 9.17.1.13; 9.17.1.15; 9.17.1.20; 9.18.1; 9.18.1.3; 9.18.2; 9.18.2.5; 9.18.2.7; 9.19.1 Fixed in — No fix listed CNA
  • Cisco Firepower Threat Defense Software VendorCisco Affected 7.0.0; 7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.0.2.1; 7.0.3; 7.0.4; 7.0.5; 7.1.0; 7.1.0.1; 7.1.0.2; 7.1.0.3; 7.2.0; 7.2.0.1; 7.2.1; 7.2.2; 7.2.3; 7.3.0; 7.3.1; 7.3.1.1 Fixed in — No fix listed CNA

CPE configurations NVD · 51

CPEVersionsRoleVendor
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:*:*:*:*:*:*:*7.0.0VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0.1:*:*:*:*:*:*:*7.0.0.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1:*:*:*:*:*:*:*7.0.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1.1:*:*:*:*:*:*:*7.0.1.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2:*:*:*:*:*:*:*7.0.2VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2.1:*:*:*:*:*:*:*7.0.2.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.3:*:*:*:*:*:*:*7.0.3VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.4:*:*:*:*:*:*:*7.0.4VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.5:*:*:*:*:*:*:*7.0.5VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0:*:*:*:*:*:*:*7.1.0VulnerableCisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:*:*:*:*:*:*:* Versions 7.0.0 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0.1:*:*:*:*:*:*:* Versions 7.0.0.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1:*:*:*:*:*:*:* Versions 7.0.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1.1:*:*:*:*:*:*:* Versions 7.0.1.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2:*:*:*:*:*:*:* Versions 7.0.2 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2.1:*:*:*:*:*:*:* Versions 7.0.2.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.3:*:*:*:*:*:*:* Versions 7.0.3 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.4:*:*:*:*:*:*:* Versions 7.0.4 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.5:*:*:*:*:*:*:* Versions 7.0.5 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0:*:*:*:*:*:*:* Versions 7.1.0 Vulnerable ·Cisco
Show 41 more CPE
CPEVersionsRoleVendor
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.1:*:*:*:*:*:*:*7.1.0.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.2:*:*:*:*:*:*:*7.1.0.2VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.3:*:*:*:*:*:*:*7.1.0.3VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0:*:*:*:*:*:*:*7.2.0VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0.1:*:*:*:*:*:*:*7.2.0.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.1:*:*:*:*:*:*:*7.2.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.2:*:*:*:*:*:*:*7.2.2VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.3:*:*:*:*:*:*:*7.2.3VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.0:*:*:*:*:*:*:*7.3.0VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1:*:*:*:*:*:*:*7.3.1VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1.1:*:*:*:*:*:*:*7.3.1.1VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.1:*:*:*:*:*:*:*9.16.1VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.1.28:*:*:*:*:*:*:*9.16.1.28VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2:*:*:*:*:*:*:*9.16.2VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.3:*:*:*:*:*:*:*9.16.2.3VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.7:*:*:*:*:*:*:*9.16.2.7VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.11:*:*:*:*:*:*:*9.16.2.11VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.13:*:*:*:*:*:*:*9.16.2.13VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.14:*:*:*:*:*:*:*9.16.2.14VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3:*:*:*:*:*:*:*9.16.3VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.3:*:*:*:*:*:*:*9.16.3.3VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.14:*:*:*:*:*:*:*9.16.3.14VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.15:*:*:*:*:*:*:*9.16.3.15VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.19:*:*:*:*:*:*:*9.16.3.19VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.23:*:*:*:*:*:*:*9.16.3.23VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4:*:*:*:*:*:*:*9.16.4VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4.9:*:*:*:*:*:*:*9.16.4.9VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1:*:*:*:*:*:*:*9.17.1VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.7:*:*:*:*:*:*:*9.17.1.7VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.9:*:*:*:*:*:*:*9.17.1.9VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.10:*:*:*:*:*:*:*9.17.1.10VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.11:*:*:*:*:*:*:*9.17.1.11VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.13:*:*:*:*:*:*:*9.17.1.13VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.15:*:*:*:*:*:*:*9.17.1.15VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.20:*:*:*:*:*:*:*9.17.1.20VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.1:*:*:*:*:*:*:*9.18.1VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.1.3:*:*:*:*:*:*:*9.18.1.3VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.2:*:*:*:*:*:*:*9.18.2VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.2.5:*:*:*:*:*:*:*9.18.2.5VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.2.7:*:*:*:*:*:*:*9.18.2.7VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:9.19.1:*:*:*:*:*:*:*9.19.1VulnerableCisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.1:*:*:*:*:*:*:* Versions 7.1.0.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.2:*:*:*:*:*:*:* Versions 7.1.0.2 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.3:*:*:*:*:*:*:* Versions 7.1.0.3 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0:*:*:*:*:*:*:* Versions 7.2.0 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0.1:*:*:*:*:*:*:* Versions 7.2.0.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.1:*:*:*:*:*:*:* Versions 7.2.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.2:*:*:*:*:*:*:* Versions 7.2.2 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.3:*:*:*:*:*:*:* Versions 7.2.3 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.0:*:*:*:*:*:*:* Versions 7.3.0 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1:*:*:*:*:*:*:* Versions 7.3.1 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1.1:*:*:*:*:*:*:* Versions 7.3.1.1 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.1:*:*:*:*:*:*:* Versions 9.16.1 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.1.28:*:*:*:*:*:*:* Versions 9.16.1.28 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2:*:*:*:*:*:*:* Versions 9.16.2 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.3:*:*:*:*:*:*:* Versions 9.16.2.3 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.7:*:*:*:*:*:*:* Versions 9.16.2.7 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.11:*:*:*:*:*:*:* Versions 9.16.2.11 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.13:*:*:*:*:*:*:* Versions 9.16.2.13 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.2.14:*:*:*:*:*:*:* Versions 9.16.2.14 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3:*:*:*:*:*:*:* Versions 9.16.3 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.3:*:*:*:*:*:*:* Versions 9.16.3.3 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.14:*:*:*:*:*:*:* Versions 9.16.3.14 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.15:*:*:*:*:*:*:* Versions 9.16.3.15 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.19:*:*:*:*:*:*:* Versions 9.16.3.19 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.3.23:*:*:*:*:*:*:* Versions 9.16.3.23 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4:*:*:*:*:*:*:* Versions 9.16.4 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.16.4.9:*:*:*:*:*:*:* Versions 9.16.4.9 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1:*:*:*:*:*:*:* Versions 9.17.1 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.7:*:*:*:*:*:*:* Versions 9.17.1.7 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.9:*:*:*:*:*:*:* Versions 9.17.1.9 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.10:*:*:*:*:*:*:* Versions 9.17.1.10 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.11:*:*:*:*:*:*:* Versions 9.17.1.11 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.13:*:*:*:*:*:*:* Versions 9.17.1.13 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.15:*:*:*:*:*:*:* Versions 9.17.1.15 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.17.1.20:*:*:*:*:*:*:* Versions 9.17.1.20 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.1:*:*:*:*:*:*:* Versions 9.18.1 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.1.3:*:*:*:*:*:*:* Versions 9.18.1.3 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.2:*:*:*:*:*:*:* Versions 9.18.2 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.2.5:*:*:*:*:*:*:* Versions 9.18.2.5 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.18.2.7:*:*:*:*:*:*:* Versions 9.18.2.7 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:9.19.1:*:*:*:*:*:*:* Versions 9.19.1 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-20042
  2. 2026-10-03 Alias added: GHSA-2c63-fqw2-3fhm

References

Advisory 1

  • TI-2025-14628 Buffer overflow in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.9
  • TI-2016-05454 Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on… KEVCVSS 3.1HIGH 8.8
  • TI-2023-06973 Authentication bypass in Cisco Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.1
  • TI-2026-82192 Denial of service in Cisco Secure Firewall ASA and FTD SSL VPN KEVCVSS 3.1HIGH 8.6
  • TI-2026-16533 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense… KEVCVSS 3.1HIGH 8.6
  • TI-2025-14657 Missing authorization in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1HIGH 8.6
See all 354 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences