CVE intelligence and bounded remediation

CVE-2023-20270 — Cisco Firepower Threat Defense security vulnerability

Medium CVSS 5.8

A vulnerability in the interaction between the Server Message Block (SMB) protocol preprocessor and the Snort 3 detection engine for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the configured policies or cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error-checking when the Snort 3 detection engine is processing SMB traffic. An attacker could exploit this vulnerability by sending a crafted SMB packet stream through an affected device. A successful exploit could allow the attacker to cause the Snort process to reload, resulting in a DoS condition.

Severity
Medium
CVSS
5.8 (3.1)
Published
2023-11-01
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20

Affected products

  • cisco / firepower_threat_defense / 7.1.0
  • cisco / firepower_threat_defense / 7.1.0.1
  • cisco / firepower_threat_defense / 7.1.0.2
  • cisco / firepower_threat_defense / 7.1.0.3
  • cisco / firepower_threat_defense / 7.2.0
  • cisco / firepower_threat_defense / 7.2.0.1

Showing 6 representative product identities from 12 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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