defence in depth.

UPDATE [2011-10-15]: The issues described in this post have now been resolved by Apple. Users running OS X Lion 10.7.2 or security update 2011-006 are no longer affected by the vulnerabilities detailed below (CVE-2011-3435 and CVE-2011-3436). For further details on this security update please see Apple's advisory . In 2009 I posted an article on Cracking Mac OS X passwords . Whilst this post has been quite popular, it was written for OS X 10.6 and prior. Since the release of Mac OS X Lion (10.7) in July, I have received numerous requests for an update. Typically, I would have just updated the existing article without the need for a new post. However, during my research I discovered something interesting about OS X Lion that I'd like to share. In previous versions of OS X (10.6, 10.5, 10.4) the process to extract user password hashes has been the same: obtain the user's GeneratedUID and then use that ID to extract hashes from a specific user's shadow file (See my pr

In Part 1 of the “LM/NTLMv1 Challenge/Response Authentication” series I discussed how both the LANMAN/NTLMv1 protocols operate and the weaknesses that plague these protocols. In this post I will demonstrate how attackers leverage these weaknesses to exploit the LANMAN/NTLMv1 protocols in order to compromise user credentials. For the remainder of this article I will be focusing on attacking the SMB protocol (Windows file sharing) as this is where LANMAN/NTLMv1 is most commonly used. Capturing the Response In order to capture a client’s LANMAN/NTLMv1 response, attackers will often utilise one of two methods: Force the client host to connect to them Conduct a man-in-the-middle (MITM) attack and “sniff” the client’s response To demonstrate these methods, I will be using the Metasploit Framework or Cain and Abel respectively. Metasploit In order for a client host to connect to us, we first need to create a listening SMB service that will accept incoming connections. Fo

The Microsoft Windows platform uses a myriad of protocols to authenticate users across a network. Two such protocols widely in use today are the LANMAN challenge/response and NTLMv1 protocols. Whilst newer, more secure protocols (such as NTLMv2) are ready to take their place, LANMAN challenge/response and NTLMv1 are still widely deployed today for reasons of interoperability. As with most things Microsoft-related, ubiquity often equates to exploitability. In this two part series I will discuss how the LANMAN challenge/response and NTLMv1 protocols operate, how malicious users can take advantage of their shortcomings, and best practice recommendations for securely deploying these protocols. Microsoft Windows supports two primary algorithms for locally authenticating users. These algorithms generate what’s known as an “LM Hash” or an “NT Hash”. Enabled by default in Windows NT, 2000, XP, and Server 2003, the LM Hash has become synonymous with bad hashing practices over the years