Many administrators prefer ASA 9.1(7) Interim releases due to their stability and lower memory footprint on older hardware.
Because ASA firewalls perform encryption, their software is classified as a "munition" under U.S. Export Administration Regulations (EAR). Cisco legally cannot host public downloads for K9 images. You must prove you are not in an embargoed country (e.g., North Korea, Syria, Iran) by logging into a SmartNet contract. cisco asa 5505 ios download
The last supported software version for the ASA 5505 is or, with a RAM upgrade (512MB required), up to 9.2(4) and unstable support for 9.4(2) . The 5505's limited RAM (256MB default) is its Achilles' heel. Many administrators prefer ASA 9
The ASA 5505 is an older device with limited RAM. Newer versions of ASA software require more memory. Cisco legally cannot host public downloads for K9 images
Products > Security > Firewalls > Next-Generation Firewalls (NGFW) > ASA 5500-X Series Next-Generation Firewalls > ASA 5505 Adaptive Security Appliance. You generally need a valid Service Contract (SmartNet)