Read the docs
TI-2019-09473 Aliases CVE-2019-12677GHSA-wvvv-6xf9-8f8r

Cisco Adaptive Security Appliance Software SSL VPN Denial of Service Vulnerability

Priority LOW 32CWE-172Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

A vulnerability in the Secure Sockets Layer (SSL) VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition that prevents the creation of new SSL/Transport Layer Security (TLS) connections to an affected device. The vulnerability is due to incorrect handling of Base64-encoded strings. An attacker could exploit this vulnerability by opening many SSL VPN sessions to an affected device. The attacker would need to have valid user credentials on the affected device to exploit this vulnerability. A successful exploit could allow the attacker to overwrite a special system memory location, which will eventually result in memory allocation errors for new SSL/TLS sessions to the device, preventing successful establishment of these sessions. A reload of the device is required to recover from this condition. Established SSL/TLS connections to the device and SSL/TLS connections through the device are not affected. Note: Although this vulnerability is in the SSL VPN feature, successful exploitation of this vulnerability would affect all new SSL/TLS sessions to the device, including management sessions.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01526 74th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco Adaptive Security Appliance (ASA) Softwareall versions—No fix listedCNA
  • Cisco Adaptive Security Appliance (ASA) Software VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 12

CPEVersionsRoleVendor
cpe:2.3:a:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*9.3 to before 9.3.3.9VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*before 9.1.7.4; 9.2 to before 9.2.4.8; 9.4 to before 9.4.2.11; 9.5 to before 9.5.2.5; 9.6 to before 9.6.2VulnerableCisco
cpe:2.3:h:cisco:asa_5505:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5510:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5512-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5515-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5520:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5525-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5550:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5555-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
  • cpe:2.3:a:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* Versions 9.3 to before 9.3.3.9 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* Versions before 9.1.7.4; 9.2 to before 9.2.4.8; 9.4 to before 9.4.2.11; 9.5 to before 9.5.2.5; 9.6 to before 9.6.2 Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5505:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5510:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5512-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5515-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5520:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5525-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5550:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5555-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
Show 2 more CPE
CPEVersionsRoleVendor
cpe:2.3:h:cisco:asa_5580:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asa_5585-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
  • cpe:2.3:h:cisco:asa_5580:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asa_5585-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco

Remediation

No fixed version listed by the sources yet.

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Cisco Adaptive Security Appliance (ASA) Software n/a

    8 records Highest priority Priority MEDIUM 4 MEDIUM, 4 LOW

    Other records, highest priority first

    • TI-2019-11370 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software IKEv1 Denial of Service VulnerabilityPriority MEDIUM 47
    • TI-2019-09493 Uncontrolled resource consumption in Cisco Adaptive Security Appliance SoftwarePriority MEDIUM 43
    • TI-2019-09474 Integer underflow in Cisco Adaptive Security Appliance SoftwarePriority MEDIUM 43
    Show all 8 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-12677
  2. 2026-10-03 Alias added: GHSA-wvvv-6xf9-8f8r

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