The OS X firewall protects you from connections that come from outside of your computer. TCPBlock is a lightweight and fast application firewall for OS X 10.6 or later developed by Jo Delantis. The latest version is Leopard compatible. Little Snitch is modestly priced (US$24.95), well written and stable. Youill spend some early days training, but the payoff in the long run is that no data will leave your computer without your consent. You can manually make changes to the rules as well. If some new and unexpected outbound connection happens, youill be offered the opportunity to block it.
Sample Little Snitch Configuration As you build up confidence in each Mac OS X application and system daemon and what it connects to, and grant your permission, Little Snitch dynamically builds an outbound set of filter rules. However, outgoing connections with iChat are allowed. Mail is not allowed to connect on port 80 - as some graphics attachments in spam try to do. In the example below, the Address Book is not allowed to connect to.
In turns out that there is an excellent piece of software that can do that. As a result, for complete security, a vigilant Mac OS X user should also monitor outgoing connections.
In turn, that code could, for example, trigger the transmittal of private data on the hard disk back to the malicious Website, and thatis something thatis not controlled by the firewall. Sometimes, cleverly constructed, malicious code, coming back to a port handled by a specific application, can exploit poor code, cause a buffer to overflow, and external code brought in can be caused to execute. If that didnit happen, youid never be able to browse with the firewall enabled.
As a result, a connection to a Website can in principle bring back with it, embedded in the packets, a payload that will naturally bypass the firewall.
Thatis how the packets of data sent out trigger a response that knows how to come back to your Mac. One of the features of the TCP/IP protocol is that outgoing packets from, say, a Web browser, are tagged with both the origin and destination IP addresses. However, the firewall only blocks incoming connections. For example, SFTP or HTTP access from the outside.
Outgoing Connections BlockedĪ previous discussed how to customize the Mac OS firewall in those cases where controlled, authorized external access is required. A firewall, with Stealth Mode turned on, stops that cold. These include port scans and then probes of specific ports that look for weaknesses in applications or OS daemons that use those ports. When youire connected to the Internet directly, and your IP address is visible, hackers can generally see your Mac and construct a variety of attacks. The firewall in Mac OS X is designed to stop incoming connections. I also saw an app called radio silence and it costs 3 times less than little snitch, will it do the same job?
Im trying to block outgoing connections from my mac cause sometimes im using my iphone as a hotspot, and i have a limited data plan. It may block all types of outgoing remote access. The Block all outgoing option uses an obnoxious approach to restrict connections over TCP/UDP ports.