Attacks/Breaches
6/28/2007
07:35 AM
50%
50%

Not One Size Fits All

One man's firewall is another man's kludge

3:35 PM -- Sometimes, what's good for one application just isn't good for another.

I've been in the game for a long time and get to see a lot of interesting tactics to prevent exploitation. Recently, I've been involved in auditing a software application, and one of the interesting aspects is how security theory varies from one technology to another.

With Websites, for instance, one of the reasons firewalls have proven to be fairly overkill is because often attackers are coming from addresses where many other people are also originating from (through network address translation). So you can't simply block by an IP address -- yet you feel you must block by them because you are getting attacked by an IP address.

Now look at software. If software running on your desktop detects that someone is attempting to do something malicious, it may be OK to block the request completely -- unlike with a firewall. Who cares if it breaks for a single instance of a single Web page? It's far better than having your local machine compromised. Rather than attempting to handle an error, let your application fail in a safe way. When the system starts acting responsibly again, your application can start running again in a sane way.

While the network can cause major outages if it fails, the worst that a local process can do is cause you to reboot. Setting up a denial-of-service situation on the desktop affects one user temporarily, whereas on the network, tens of thousands of users, as in the case of AOL's proxies.

One is acceptable; the other can be a significant detriment to your business. Different security people work on different systems and with different paradigms, so remember that one security professional's advice on blocking exploits does not fit all circumstances, especially if they aren't working in the same industry you are.

— RSnake is a red-blooded lumberjack whose rants can also be found at Ha.ckers and F*the.net. Special to Dark Reading.

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Flash Poll
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2015-0714
Published: 2015-05-02
Multiple cross-site scripting (XSS) vulnerabilities in Cisco Finesse Server 10.0(1), 10.5(1), 10.6(1), and 11.0(1) allow remote attackers to inject arbitrary web script or HTML via unspecified parameters, aka Bug ID CSCut53595.

CVE-2014-3598
Published: 2015-05-01
The Jpeg2KImagePlugin plugin in Pillow before 2.5.3 allows remote attackers to cause a denial of service via a crafted image.

CVE-2014-8361
Published: 2015-05-01
The miniigd SOAP service in Realtek SDK allows remote attackers to execute arbitrary code via a crafted NewInternalClient request.

CVE-2015-0237
Published: 2015-05-01
Red Hat Enterprise Virtualization (RHEV) Manager before 3.5.1 ignores the permission to deny snapshot creation during live storage migration between domains, which allows remote authenticated users to cause a denial of service (prevent host start) by creating a long snapshot chain.

CVE-2015-0257
Published: 2015-05-01
Red Hat Enterprise Virtualization (RHEV) Manager before 3.5.1 uses weak permissions on the directories shared by the ovirt-engine-dwhd service and a plugin during service startup, which allows local users to obtain sensitive information by reading files in the directory.

Dark Reading Radio
Archived Dark Reading Radio
Join security and risk expert John Pironti and Dark Reading Editor-in-Chief Tim Wilson for a live online discussion of the sea-changing shift in security strategy and the many ways it is affecting IT and business.