CVE-2019-15256: Cisco Adaptive Security Appliance Software

High severity, CVSS 8.6. EPSS: 2% chance of exploitation in the next 30 days.

A vulnerability in the Internet Key Exchange version 1 (IKEv1) feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper management of system memory. An attacker could exploit this vulnerability by sending malicious IKEv1 traffic to an affected device. The attacker does not need valid credentials to authenticate the VPN session, nor does the attacker's source address need to match a peer statement in the crypto map applied to the ingress interface of the affected device. An exploit could allow the attacker to exhaust system memory resources, leading to a reload of an affected device.

Affected products

  • Cisco Adaptive Security Appliance Software: from 9.7, before 9.8.4.10 (fixed in 9.8.4.10); from 9.9, before 9.9.2.47 (fixed in 9.9.2.47); from 9.10, before 9.10.1.30 (fixed in 9.10.1.30); from 9.12, before 9.12.2.5 (fixed in 9.12.2.5)
  • Cisco ASA 5505 Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5510 Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5512-X Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5515-X Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5520 Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5525-X Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5540 Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5545-X Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5550 Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5555-X Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco ASA 5580 Firmware: version 9.9(2.4) only; version 201.4(1.21) only
  • Cisco Secure Firewall Threat Defense: from 6.2.0, before 6.2.3.11 (fixed in 6.2.3.11); from 6.3.0, before 6.3.0.2 (fixed in 6.3.0.2)

Published 2019-10-02. Last modified 2026-08-11.