Caido

Download & Installation ​

"This site can't be reached." ​

When attempting to download Caido, if you encounter a "This site can't be reached" error due to a request time out, your IP address may be blocked by the storage provider's firewall.

If this is the case, try using a VPN or changing your DNS provider and refreshing the page.

"The SUID sandbox helper binary was found, but is not configured correctly." ​

If you're using Linux and have installed Caido using the AppImage installation method, you may encounter an error, accompanied by a message similar to the following:

[142547:0410/141348.635410:FATAL:setuid_sandbox_host.cc(163)] The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I'm aborting now. You need to make sure that /tmp/.mount_caido-PMiQot/chrome-sandbox is owned by root and has mode 4755.

This error happens due to AppArmor, the Linux application security system. Each time Caido is launched, it loads itself in the tmp folder as a virtual file system before execution. This means there is no hook to add an AppArmor profile, which defines exactly what a certain program is allowed and not allowed to do in the context of the operating system.

There are three ways to work around this issue (listed in order, beginning with the most secure to the least secure methods):

INFO

For the following commands throughout each of the three methods, be sure to replace /path/to/caido-desktop-vX.XX.X-linux-<architecture>.AppImage with the path, versioning, and architecture to the AppImage file that is appropriate to you. If you renamed the file, account for that as well.

Create an AppArmor Profile for Caido (Preferred Method): ​

  1. Create a new profile file in the AppArmor profile directory with:
sudo nano /etc/apparmor.d/appimage.caido
  1. The file's content should be:
abi <abi/4.0>,
include <tunables/global>

profile appimage.caido /path/to/caido-desktop-vX.XX.X-linux-<architecture>.AppImage  flags=(unconfined) {
userns,

include if exists <local/appimage.caido>
}
  1. Read and load the profile with:
apparmor_parser -r /etc/apparmor.d/appimage.caido

Run Caido without a Sandbox ​

To disable the AppArmor sandbox security restrictions, use the --no-sandbox argument when launching Caido:

/path/to/caido-desktop-vX.XX.X-linux-<architecture>.AppImage --no-sandbox

If you would like to apply this to every launch:

  1. Create a file with the .desktop extension located in either:
  • ~/.local/share/applications/ for the current user account.
  • /usr/share/applications/ for all user accounts.
  1. The file's content should be:
[Desktop Entry]
Version=1.0
Name=Caido
Comment=Caido - A platform for secure vulnerability management
Exec=/path/to/caido-desktop-vX.XX.X-linux-<architecture>.AppImage --no-sandbox
Icon=/path/to/caido-icon.png
Terminal=false
Type=Application
Categories=Security;Utility;Networking;
StartupNotify=true
  1. Refresh the desktop application icon cache with:
sudo update-icon-caches /usr/share/icons/*

TIPS

To disable AppArmor globally, run the following command:

sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0