Outbound web filter (forward proxy): what it is and how it is attacked
Checks and records everything staff and servers send out to the internet.
Also known as
- forward proxy
- secure web gateway
- SWG
- web filter
- web proxy
Typing any of them into the editor finds this object.
Why it matters on a security diagram
It is often the only place outbound traffic is recorded, which makes it the place data leaving is noticed. It also holds a signing certificate that every company machine has been told to trust.
How it gets attacked, and what reduces it
How it gets attacked
- Traffic routed around it entirely
- Blending in with ordinary web traffic so nothing looks unusual
- The signing certificate it uses to open encrypted traffic, which every company machine already trusts
What reduces it
- Route outbound traffic through it by policy, not by hoping
- Protect its signing certificate as you would a domain controller, since every company machine already trusts it
- Alert on traffic that leaves by any other path
Where it sits
- Group
- Security and edge · The things that sit in front of something else and check what is trying to reach it.
- Whose side, by default
- Ours · Belongs to the organisation the diagram is about.
- Catalogue identifier
- web-filter
Reviewed . CC BY 4.0.
Others in security and edge
- FirewallNGFW · packet filterDecides which connections are allowed between two networks.
- Web app shieldWAF · web application firewallChecks visits to your website and blocks the ones that look like an attack.
- Traffic splitterload balancer · LB · ADCSpreads incoming requests across several servers.
- Global content cacheCDN · content delivery network · edge cacheCopies your content to servers worldwide so pages load faster.
- API front doorAPI gatewayOne controlled entrance for the automatic requests other software makes of yours, without a person involved.
- Endpoint protectionEDR · antivirus · AV · XDRSoftware on each computer watching for hostile behaviour.
- Log collectorSIEM · log server · syslogCollects the records of what happened, from every computer and system, into one place.
- Secrets storevault · secrets manager · credential store · password safeThe safe where passwords, keys and certificates are kept.
- Encryption key serviceKMS · key management service · key vault · HSM · customer-managed keyThe service that holds the keys used to scramble stored data, and decides who may use them.
- Cloud activity recordCloudTrail · activity log · control plane log · audit trailThe provider's own record of every change made to the cloud, and of who made it.
The security and edge group lists all 11 of them side by side.
Outbound web filter on your own diagram
Open the editor, press N, and type forward proxy. The object is placed and connected to whatever was selected, and Tab adds the next one already joined to it. Nothing is uploaded: the page is served with a Content Security Policy that forbids the browser from making any outbound request at all.
Open the diagram maker