Cisco released security advisories to address multiple vulnerabilities in Cisco devices and software. For information about the vulnerabilities and the attacking vectors, please refer to the corresponding security advisories at the vendor's website.
Please note that Cisco Small Business SPA500 Series IP Phones have reached End-Of-Life (EOL). No security updates will be provided after that. System administrators should arrange a device migration according to the official announcement by Cisco:
https://www.cisco.com/c/en/us/products/collateral/collaboration-endpoints/small-business-spa500-series-ip-phones/eos-eol-notice-c51-741207.html
For detailed information of the affected products, please refer to the section "Affected Products" of corresponding security advisory at vendor's website.
Depending on the vulnerabilities being exploited, a successful exploitation could lead to privilege escalation or spoofing of affected system.
Software updates for affected systems are now available. System administrators of affected systems should follow the recommendations provided by the product vendor and take immediate actions to mitigate the risk. For detailed information of the available patches, please refer to the section "Fixed Software" of corresponding security advisory at vendor's website.
System administrators should contact their product support vendors for the fixes and assistance.