
LAN port scan forbidder by garywill
Forbid non-LAN webs to access LAN or localhost. An anti-scan protection
You'll need Firefox to use this extension
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About this extension
Forbid untrusted web to scan localhost or LAN. Browser addon.
What
Webs can try to fetch
Although browsers have cross-domain protections, webs can't read response contents, but can still see the connection succeeds or fails.
There're already reports that some websites using that as tracking fingerprint.
So
Forbid any website behaviors trying to connect to your LAN or localhost, if user is visiting the website via their domains or public IP addresses. (Read the source code
Fallback operation
If user find a web broken, user can temporary set this addon disabled via toolbar button for:
(above can be set as keyboard shortcuts)
there's showy toolbar button badge indicating disabling status.
Cases when web LAN scan is properly used
Not all LAN-port-scan are evil.
What
Webs can try to fetch
127.0.0.1:xxxx
or 192.168.Y.Z:xxxx
to scan your open ports in LAN.Although browsers have cross-domain protections, webs can't read response contents, but can still see the connection succeeds or fails.
There're already reports that some websites using that as tracking fingerprint.
A web for testing: http://samy.pl/webscan/
So
Forbid any website behaviors trying to connect to your LAN or localhost, if user is visiting the website via their domains or public IP addresses. (Read the source code
background.js
to see the logic)Using JS library whitequark/ipaddr.js (MIT License) v2.0.0 to judge IP range.
Fallback operation
If user find a web broken, user can temporary set this addon disabled via toolbar button for:
- this one tab
- this one tab and new tabs opened by this tab
- this one window (Firefox only)
- globally
(above can be set as keyboard shortcuts)
there's showy toolbar button badge indicating disabling status.
Cases when web LAN scan is properly used
Not all LAN-port-scan are evil.
- Some manufacturers provide web for user's browser to scan LAN for their product that need updating.
- Some softwares use
127.0.0.1
communication to interact between native program and web.
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PermissionsLearn more
This add-on needs to:
- Access browser tabs
- Access your data for all web sites
More information
- Add-on Links
- Version
- 0.5.0
- Size
- 36.18 kB
- Last updated
- a year ago (13 Jan 2022)
- Related Categories
- Licence
- GNU General Public Licence v2.0
- Version History
- Tags
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Release notes for 0.5.0
support setting keyboard shortcuts
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