CVE intelligence and bounded remediation

CVE-2018-0177 — Cisco Ios Xe security vulnerability

High CVSS 7.8

A vulnerability in the IP Version 4 (IPv4) processing code of Cisco IOS XE Software running on Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches could allow an unauthenticated, remote attacker to cause high CPU utilization, traceback messages, or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain IPv4 packets. An attacker could exploit this vulnerability by sending specific IPv4 packets to an IPv4 address on an affected device. A successful exploit could allow the attacker to cause high CPU utilization, traceback messages, or a reload of the affected device that leads to a DoS condition. If the switch does not reboot when under attack, it would require manual intervention to reload the device. This vulnerability affects Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches that are running Cisco IOS XE Software Release 16.1.1 or later, until the first fixed release, and are configured with an IPv4 address. Cisco Bug IDs: CSCvd80714.

Severity
High
CVSS
7.8 (2.0)
Published
2018-03-28
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-19

Affected products

  • cisco / ios_xe / denali-16.3.1
  • cisco / ios_xe / denali-16.3.3

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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