CVE intelligence and bounded remediation

CVE-2021-40125 — Cisco Firepower Threat Defense security vulnerability

Medium CVSS 6.5

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. This vulnerability is due to improper control of a resource. An attacker with the ability to spoof a trusted IKEv2 site-to-site VPN peer and in possession of valid IKEv2 credentials for that peer could exploit this vulnerability by sending malformed, authenticated IKEv2 messages to an affected device. A successful exploit could allow the attacker to trigger a reload of the device.

Severity
Medium
CVSS
6.5 (3.1)
Published
2021-10-27
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-416, CWE-400

Affected products

  • cisco / firepower_threat_defense
  • cisco / adaptive_security_appliance_software
  • cisco / asa_5512-x_firmware / 009.016(001.025)
  • cisco / asa_5505_firmware / 009.016(001.025)
  • cisco / asa_5515-x_firmware / 009.016(001.025)

Showing 5 representative product identities from 17 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Use-after-free, double free, and expired resource use

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

Check exposure

  • Trace ownership, references, callbacks, asynchronous tasks, and teardown paths around the affected object or resource.
  • Identify reachable inputs and timing or state transitions that can release the object while references remain.
  • Confirm affected builds, allocators, feature flags, architectures, and process privileges.

Remediate safely

  • Apply the maintained ownership or lifetime fix and rebuild all artifacts containing the affected native code.
  • Use explicit ownership, safe reference management, cancellation and join semantics, and idempotent teardown.
  • Add deterministic lifetime tests plus isolated sanitizer and concurrency coverage for shutdown and error paths.

Authoritative sources

Complete CVE record and remediation plan

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