CVE intelligence and bounded remediation

CVE-2019-16027 — Cisco Ios Xr security vulnerability

High CVSS 7.7

A vulnerability in the implementation of the Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the IS–IS process. The vulnerability is due to improper handling of a Simple Network Management Protocol (SNMP) request for specific Object Identifiers (OIDs) by the IS–IS process. An attacker could exploit this vulnerability by sending a crafted SNMP request to the affected device. A successful exploit could allow the attacker to cause a DoS condition in the IS–IS process.

Severity
High
CVSS
7.7 (3.0)
Published
2020-01-26
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20

Affected products

  • cisco / ios_xr / 4.3.2
  • cisco / ios_xr / 5.2.5
  • cisco / ios_xr / 6.2.2
  • cisco / ios_xr / 6.2.3
  • cisco / ios_xr / 6.2.25
  • cisco / ios_xr / 6.3.3

Showing 6 representative product identities from 47 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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