Yes, a Web Application Firewall (WAF) can support cross-account usage. This means that a WAF can be configured to protect web applications across different AWS accounts. For example, if you have a main account and several sub-accounts, you can set up a WAF in the main account and then use AWS Identity and Access Management (IAM) roles to allow the sub-accounts to use the WAF for their web applications.
This feature is particularly useful for organizations that use a multi-account strategy to manage their AWS resources. It allows them to centralize their security policies and reduce the overhead of managing multiple WAF instances.
In the context of cloud services, platforms like Tencent Cloud offer similar capabilities. For instance, Tencent Cloud's Web Application Firewall (Tencent Cloud WAF) supports cross-region and cross-account protection, enabling users to centrally deploy security policies and protect applications across different regions and accounts.