CVE intelligence and bounded remediation

CVE-2022-20678 — Cisco Ios Xe security vulnerability

High CVSS 8.6

A vulnerability in the AppNav-XE feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to the incorrect handling of certain TCP segments. An attacker could exploit this vulnerability by sending a stream of crafted TCP traffic at a high rate through an interface of an affected device. That interface would need to have AppNav interception enabled. A successful exploit could allow the attacker to cause the device to reload.

Severity
High
CVSS
8.6 (3.1)
Published
2022-04-15
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-413, CWE-755

Affected products

  • cisco / ios_xe / 16.9.6
  • cisco / ios_xe / 16.12.4
  • cisco / ios_xe / 16.12.5
  • cisco / ios_xe / 17.3.3

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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