CVE intelligence and bounded remediation

CVE-2022-20856 — Cisco Ios Xe security vulnerability

High CVSS 8.6

A vulnerability in the processing of Control and Provisioning of Wireless Access Points (CAPWAP) Mobility messages in Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to a logic error and improper management of resources related to the handling of CAPWAP Mobility messages. An attacker could exploit this vulnerability by sending crafted CAPWAP Mobility packets to an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device. This would cause the device to reload, resulting in a DoS condition.

Severity
High
CVSS
8.6 (3.1)
Published
2022-09-30
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-664

Affected products

  • cisco / ios_xe / 17.3.4c

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

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Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

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