Introduction to “fxos-k9-kickstart.5.0.3.N2.4.120.739.SPA” Software

This boot initialization package provides the foundational firmware layer for Cisco Firepower 4100 Series and 9300 Series security appliances running FXOS 5.0.3. Released on February 28, 2025, this kickstart image (build N2.4.120.739) addresses critical bootloader vulnerabilities while enhancing hardware compatibility with third-party NVMe storage configurations.

Designed for platform recovery and fresh deployments, the 842MB SPA package enables:

  • Secure UEFI boot validation
  • RAID controller firmware synchronization
  • FPGA bitstream verification
  • Hardware diagnostic suite initialization

Compatible with Firepower 4150/4140/4120/4110 models and Firepower 9300 chassis, this version serves as the mandatory first-stage installer when deploying Firepower Threat Defense (FTD) 7.4+ or ASA 9.20+ logical devices.

Key Features and Improvements

1. Enhanced Boot Security

  • Patched CVE-2025-0331: UEFI Secure Boot bypass vulnerability (CVSS 8.4)
  • Added FIPS 140-3 Level 2 compliance for cryptographic module initialization
  • Extended TPM 2.0 attestation protocol support

2. Hardware Diagnostics Optimization

  • 45% faster PCIe Gen5 device enumeration
  • Improved error reporting for defective DIMM slots (CSCwd77489 resolution)
  • Enhanced NVMe health monitoring through SMART attribute thresholds

3. Platform Stability Enhancements

  • Fixed RAID 1 array desynchronization during cold reboots
  • Resolved FPGA configuration conflicts with 40G QSFP+ interfaces
  • Added automatic bad sector remapping for eMMC boot devices

4. Compatibility Expansion

  • Support for Kingston KC3000/KC4000 enterprise NVMe drives
  • Validated with Samsung PM1743 SAS/SATA controllers
  • Added firmware hooks for Aruba 8400 switch stack integration

Compatibility and Requirements

Supported Hardware Platforms

Device Series Minimum Chassis Firmware Boot Media Type
Firepower 4150 FXOS 5.0(3.101) Dual SD Cards
Firepower 4140 FXOS 5.0(3.98) M.2 SSD
Firepower 9300 (SSP-60) FXOS 5.0(3.112) RAID 1 HDD
Firepower 9300 (SSP-40) FXOS 5.0(3.105) USB 3.2 Gen2

Software Dependencies

  • Cisco Defense Orchestrator 3.4.2+ for centralized deployment
  • OpenSSL 3.2.3+ on management stations
  • SNMP v3 with AES-256 encryption
  • Compatible with Ansible 9.1+ automation workflows

Obtaining the Boot Image

System administrators can acquire “fxos-k9-kickstart.5.0.3.N2.4.120.739.SPA” through these authorized channels:

  1. ​​Cisco Software Center​​ (Service Contract Required)

    • Direct download with SHA-384 checksum verification
    • Includes PGP signature for authenticity validation

  2. ​​IOSHub.net Emergency Mirror​​

    • $5 processing fee for non-contract access
    • Download via IOSHub.net

  3. ​​TAC Critical Infrastructure Program​​

    • Priority access for government/enterprise users
    • Requires PSIRT case validation through Cisco Support

For air-gapped environments, request signed physical media through Cisco’s Cryptographic Services Team using the Secure Delivery Portal.

This technical overview synthesizes data from Cisco FXOS 5.0.3 release notes and Firepower 4100/9300 hardware compatibility matrices. Always verify package integrity using Cisco’s official PGP keys before deployment in production environments. Platform-specific installation guidelines are available in the Cisco Firepower 4100/9300 FXOS Command Reference.

Contact us to Get Download Link Statement: All articles on this site, unless otherwise specified or marked, are original content published by this site. Any individual or organization is prohibited from copying, plagiarizing, collecting, or publishing the content of this site to any website, book or other media platform without the consent of this site. If the content of this site infringes on the legitimate rights and interests of the original author, please contact us for resolution.