CVE intelligence and bounded remediation

CVE-2021-40114 — Cisco Firepower Threat Defense security vulnerability

High CVSS 7.8

Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper memory resource management while the Snort detection engine is processing ICMP packets. An attacker could exploit this vulnerability by sending a series of ICMP packets through an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device, causing the device to reload.

Severity
High
CVSS
7.8 (2.0)
Published
2021-10-27
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-770, CWE-401

Affected products

  • cisco / firepower_threat_defense
  • cisco / secure_firewall_management_center / 2.9.14.0
  • cisco / secure_firewall_management_center / 2.9.15
  • cisco / secure_firewall_management_center / 2.9.16
  • cisco / secure_firewall_management_center / 2.9.17
  • cisco / unified_threat_defense

Showing 6 representative product identities from 11 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

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