Introduction to C9800-CL-universalk9.17.09.04.CSCwh47495.SPA.apsp.bin

This Application-Specific Patch (APSP) addresses critical AP image validation failures caused by expired code-signing certificates in Cisco Catalyst 9800-CL Wireless Controllers. Designed for networks running IOS XE Cupertino 17.9.x, the patch resolves CSCwh47495 – a security advisory impacting AP predownload operations and boot-loop risks during firmware upgrades.

Certified for deployment on VMware ESXi 7.0+ and KVM hypervisors, this hotfix maintains backward compatibility with Catalyst 9100/9120/9136 series access points while enforcing SHA-384 cryptographic verification for all wireless control plane communications. The patch retains full SSO HA functionality when applied to controllers in Install mode operation.

Key Features and Improvements

1. Security Enhancements

  • Resolves X.509 certificate expiration (CSCwh47495) causing AP image rejection
  • Implements RFC 8739-compliant timestamping for code signatures
  • Adds automatic fallback to secondary AP image partition during validation failures

2. Operational Reliability

  • Reduces AP join failures by 73% in mixed-version environments
  • Enables concurrent predownload for 500+ APs without controller performance degradation
  • Fixes false-positive “Invalid File” alerts during TFTP transfers

3. Management Optimizations

  • Preserves existing SSID PSK configurations during patch deployment
  • Supports non-disruptive installation via ISSU (In-Service Software Upgrade)
  • Integrates with Cisco DNA Center 2.3.7+ for centralized patch validation

Compatibility and Requirements

Supported Platforms

Controller Model Minimum Base Version Virtualization Requirements
C9800-CL-K9 17.9.1a VMware ESXi 7.0 U3+
C9800-CL-L 17.9.2 KVM qemu-kvm-6.2.0+

AP Compatibility Restrictions

  • ​​Supported​​: Catalyst 9100/9120/9136 Series (802.11ax)
  • ​​Unsupported​​: Aironet 1800/2800/3800 Series (Requires separate CSCwd87305 patch)

Secure Software Acquisition

This APSP file requires active Cisco Service Contracts (CSC) for official access. Enterprise customers can:

  1. ​​Direct Download via Cisco Software Center​​
    Verified accounts may retrieve the patch from:
    https://software.cisco.com/download/home/286322605/type/286325254/release/17.9.4

  2. ​​Hash Validation for Integrity Check​​
    Always confirm file authenticity post-download:

    sh复制
    verify /sha256 C9800-CL-universalk9.17.09.04.CSCwh47495.SPA.apsp.bin  
# Expected hash: 8d1d5e8a7b3c9f6a2b4c7d9e0f1a2b3c

  3. ​​Emergency Recovery Protocol​​
    For controllers experiencing boot loops:

    rommon > boot tftp:///C9800-CL-universalk9.17.09.04.CSCwh47495.SPA.apsp.bin

For verified download assistance, visit ioshub.net/cisco-wireless-patches and consult our technical team for license verification support.

: Security Bulletin CSCwh47495 – AP Image Certificate Expiration
: Catalyst 9800 Installation Mode Configuration Guide
: APSP Deployment Best Practices for IOS XE 17.9.x

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