CVE intelligence and bounded remediation

CVE-2024-20309 — Cisco Ios Xe security vulnerability

Medium CVSS 5.6

A vulnerability in auxiliary asynchronous port (AUX) functions of Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload or stop responding. This vulnerability is due to the incorrect handling of specific ingress traffic when flow control hardware is enabled on the AUX port. An attacker could exploit this vulnerability by reverse telnetting to the AUX port and sending specific data after connecting. A successful exploit could allow the attacker to cause the device to reset or stop responding, resulting in a denial of service (DoS) condition.

Severity
Medium
CVSS
5.6 (3.1)
Published
2024-03-27
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-828

Affected products

  • cisco / ios_xe / 3.2.0se
  • cisco / ios_xe / 3.2.1se
  • cisco / ios_xe / 3.2.2se
  • cisco / ios_xe / 3.2.3se
  • cisco / ios_xe / 3.3.0se
  • cisco / ios_xe / 3.3.0sq

Showing 6 representative product identities from 343 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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