Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Black Hat Asia
March 26-29, 2019
Singapore
Black Hat USA
August 3-8, 2019
Las Vegas, NV, USA
Black Hat Europe
December 2-5, 2019
London UK

Understanding Firewalls: Build Them Up, Tear Them Down

A presentation at Black Hat USA will walk attendees through developing a firewall for MacOS, and then poking holes in it.

Firewalls traditionally focus on traffic coming into a network (or endpoint) from the outside. Advanced threats use a number of techniques to get around that focus – and those techniques aimed at MacOS are at the heart of research being presented at Black Hat this week.

Patrick Wardle, chief research officer at Digita Security and founder of Objective-See, decided that the best way to understand the limitations and possibilities of a firewall was to build his own. The first part of his presentation at Black Hat (and a subsequent talk at DEF CON) will be about how one goes about building a firewall that looks at traffic flowing in both directions and precisely what such a firewall can be expected to stop.

(See Wardle's session, "Fire & Ice: Making and Breaking macOS Firewalls," on Thursday, August 9, at Black Hat USA)

The second part of the presentation will look at how an attacker would go about breaking through the firewall to reach the target within. Wardle says existing third-party firewalls for MacOS protect traffic in both directions and can be quite effective.

"There are some Mac malware samples that, the first thing they do when run, is enumerate the installed software and look for one of these firewall products," Wardle says. "And if they see one of these firewall products, they will actually not infect the system because they know that the firewall will basically detect them and then give away their presence to the user."

But even good firewalls are at a disadvantage to attackers because, in the Internet era, certain communications simply must be allowed. "I run through a variety of hacks where we can basically abuse trusted protocols, trusted processes. And even though the firewalls will see these connections, they will allow them because they have no way of telling that they're actually malicious," Wardle says.

Many Mac users are more trusting than they should be because of the Mac's reputation for security. It's a reputation that Wardle says is based on history and aggressive marketing – and is less deserved than was once the case.

"In my expert professional opinion, if you look at the latest version of Windows – Windows 10 – and compare it to the latest version of OS X, there's really no comparison in terms of security. The Windows operating system is just so much more secure," Wardle says. "Any attacker who wants to infect your Mac computer, if they're advanced and sophisticated enough, they are going to have no problem hacking in."

The firewall that Wardle developed for his presentation will be available on Github at the end of his session. The software will be free and open source.

Related Content:

Curtis Franklin Jr. is Senior Editor at Dark Reading. In this role he focuses on product and technology coverage for the publication. In addition he works on audio and video programming for Dark Reading and contributes to activities at Interop ITX, Black Hat, INsecurity, and ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Data Privacy Protections for the Most Vulnerable -- Children
Dimitri Sirota, Founder & CEO of BigID,  10/17/2019
Sodinokibi Ransomware: Where Attackers' Money Goes
Kelly Sheridan, Staff Editor, Dark Reading,  10/15/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
7 Threats & Disruptive Forces Changing the Face of Cybersecurity
This Dark Reading Tech Digest gives an in-depth look at the biggest emerging threats and disruptive forces that are changing the face of cybersecurity today.
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-18214
PUBLISHED: 2019-10-19
The Video_Converter app 0.1.0 for Nextcloud allows denial of service (CPU and memory consumption) via multiple concurrent conversions because many FFmpeg processes may be running at once. (The workload is not queued for serial execution.)
CVE-2019-18202
PUBLISHED: 2019-10-19
Information Disclosure is possible on WAGO Series PFC100 and PFC200 devices before FW12 due to improper access control. A remote attacker can check for the existence of paths and file names via crafted HTTP requests.
CVE-2019-18209
PUBLISHED: 2019-10-19
templates/pad.html in Etherpad-Lite 1.7.5 has XSS when the browser does not encode the path of the URL, as demonstrated by Internet Explorer.
CVE-2019-18198
PUBLISHED: 2019-10-18
In the Linux kernel before 5.3.4, a reference count usage error in the fib6_rule_suppress() function in the fib6 suppression feature of net/ipv6/fib6_rules.c, when handling the FIB_LOOKUP_NOREF flag, can be exploited by a local attacker to corrupt memory, aka CID-ca7a03c41753.
CVE-2019-18197
PUBLISHED: 2019-10-18
In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclo...