Allowlist
An access control model that denies all requests by default and permits only services or resources that have been pre-vetted and added to the list; security depends on the vetting process.
Timeline (last 90 days)
Allowlists should be written as exact hostnames rather than wildcard suffixes, because suffix matching such as *.example.net would include pre-release subdomains as well.
Allowlists (deny by default, permit one by one) are more suitable for AI agents than blocklists (allow by default, block one by one), because agents autonomously discover and call new services, and blocklists inevitably lag in an open environment.
Magic bytes sniffing must be used together with an explicit allowlist: reject on a failed match rather than guessing.
The fix is: sniff magic bytes, match against an explicit allowlist, and return 415 Unsupported Media Type for everything else, including .exe, .dmg, .zip, and any file whose first 512 bytes contain a null byte.
All Facts (4)
Allowlists should be written as exact hostnames rather than wildcard suffixes, because suffix matching such as *.example.net would include pre-release subdomains as well.
50%UnverifiedAllowlists (deny by default, permit one by one) are more suitable for AI agents than blocklists (allow by default, block one by one), because agents autonomously discover and call new services, and blocklists inevitably lag in an open environment.
50%UnverifiedMagic bytes sniffing must be used together with an explicit allowlist: reject on a failed match rather than guessing.
50%UnverifiedThe fix is: sniff magic bytes, match against an explicit allowlist, and return 415 Unsupported Media Type for everything else, including .exe, .dmg, .zip, and any file whose first 512 bytes contain a null byte.
50%