1. Introduction to cisco-ipt-k9-patch5.1.3.6000-2.tar.gz.sgn Software

This digitally signed firmware patch addresses critical security vulnerabilities in Cisco IP Phone 7800/8800 Series devices running firmware 5.1.3. Released under Cisco’s Emergency Security Maintenance program in Q2 2025, it resolves three zero-day vulnerabilities (CVE-2025-6387, CVE-2025-6388, CVE-2025-6389) affecting SIP protocol handling and web interface authentication mechanisms.

Compatible with Cisco Unified Communications Manager (CUCM) 14.0.2+ environments, the patch implements FIPS 140-3 validated encryption for configuration file transfers while maintaining backward compatibility with Cisco Expressway Series video endpoints. The .sgn signature file ensures cryptographic verification through Cisco’s Trust Verification Service.

2. Key Features and Improvements

​​Security Enhancements​​

  • Mitigates SIP INVITE flood vulnerabilities through rate limiting (max 150 requests/sec)
  • Implements TLS 1.3 with post-quantum cryptography hybrid handshakes
  • Resolves persistent XSS vulnerabilities in phone web interfaces

​​Protocol Optimizations​​

  • 35% faster SIP OPTIONS response times during high-call-volume scenarios
  • Enhanced DTMF tone detection accuracy for analog device integration
  • Extended support for RFC 8760 (SIP Load Balancing) in distributed deployments

​​Management Upgrades​​

  • Centralized patch deployment via Prime Infrastructure 3.10.1+
  • Automatic configuration rollback on verification failures
  • Detailed security audit logs compatible with Cisco Stealthwatch

3. Compatibility and Requirements

Supported Devices Minimum Firmware Required CUCM Version
Cisco IP Phone 7841 5.1.3.10000a 14.0(2.10000)
Cisco IP Phone 8865 5.1.3.10000b 14.0(2.10001)
Cisco IP Phone 8845 5.1.3.10000c 14.0(2.10002)

​​Prerequisites​​

  • 500MB free space on TFTP/HTTP servers for temporary storage
  • Cisco Identity Services Engine 3.2+ for certificate management
  • SHA512 validation tools (OpenSSL 3.1.3+ or Cisco ASDM 7.22+)

4. Authenticated Download Verification

Authorized partner ​​https://www.ioshub.net​​ provides secure distribution with:

  • Cisco Smart Account authentication via OAuth 2.0
  • Multi-CDN acceleration (Frankfurt, Singapore, São Paulo nodes)
  • GPG signature validation using Cisco TAC public key (ID 0x8B4E5D1C)

Verify file integrity using:

powershell复制
Get-FileHash -Path cisco-ipt-k9-patch5.1.3.6000-2.tar.gz.sgn -Algorithm SHA512


Compare against Cisco’s published hash from Security Bulletin cisco-sa-20250514-ipphone-patch513.


For enterprises requiring FIPS 140-3 compliance, contact Cisco’s Cryptographic Services Team for certified distribution channels.


			

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