CVE intelligence and bounded remediation

CVE-2019-15256 — Cisco Adaptive Security Appliance Software security vulnerability

High CVSS 8.6

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.

Severity
High
CVSS
8.6 (3.1)
Published
2019-10-02
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-399, CWE-400

Affected products

  • cisco / adaptive_security_appliance_software
  • cisco / firepower_threat_defense
  • cisco / asa_5505_firmware / 9.9(2.4)
  • cisco / asa_5505_firmware / 201.4(1.21)
  • cisco / asa_5510_firmware / 9.9(2.4)
  • cisco / asa_5510_firmware / 201.4(1.21)

Showing 6 representative product identities from 28 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.