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UXSS in McAfee Endpoint Security, and some extra goodies...

During the HITB2017AMS talk given in Amsterdam with @Steventseeley, I promised that I would have disclosed vulnerabilities affecting a security vendor product other than Trend Micro.

For those who have come to my blog for the first time and are looking at "insecurities" of security vendors, you might be interested as well on how we found 200+ remote code execution vulnerabilities in Trend Micro software...

But this blog post is dedicated to two McAfee products instead: McAfee Endpoint Security and SiteAdvisor Enterprise (now part of McAfee Endpoint Security). For simplicity, I will just refer to McAfee Endpoint Security for the rest of this post.

First let's demonstrate a particular type of XSS, a UXSS, considering that fact that it only affects the McAfee Endpoint Security plugin and does not depend on a particular web site or web application.

There are two different injection points:

-UXSS when user visits a red labelled web site - the payload is rendered in the BlockP…
Recent posts

Trend Micro Threat Discovery Appliance - Session Generation Authentication Bypass (CVE-2016-8584)

In the last few months, I have been testing several Trend Micro products with Steven Seeley (@steventseeley). Together, we have found more than 200+ RCE (Remote Code Execution) vulnerabilities and for the first time we presented the outcome of our research at Hack In The Box 2017 Amsterdam in April.

The presentation is available as a PDF or as a Slideshare.

Since it was not possible to cover all discovered vulnerabilities with a single presentation, this blog post will cover and analyze a further vulnerability that did not make it to the slides, and which affects the Trend Micro Threat Discovery Appliance (TDA) product.

CVE-2016-8584 - TDA Session Generation Authentication Bypass

This was an interesting vulnerability, discovered after observing that two consecutive login attempts against the web interface returned the same session_id token. Following this observation, our inference was that time factor played a role. After further analysis and reversing of the TDA libraries, the sessio…

Alcatel Lucent Omnivista or: How I learned GIOP and gained Unauthenticated Remote Code Execution (CVE-2016-9796)

It is time for another advisory or better a blog post about Alcatel Lucent Omnivista and its vulnerabilities. Omnivista is a central management network tool and it is typically used in medium/large organisation with a complex VoIP/SIP infrastructure.

Interestingly enough, this software belongs to the niche of "undownloadable" software and it requires a license to work as well. My "luck" came during an engagement where it was already installed and this post documents one of the many 0days discovered during such audit.

The reasons why I wanted to dedicate a single blog post on this vulnerability are several.

First, remote code execution (RCE) is always a sweet bug to show. Second, I strongly believe that documenting vulnerabilities in applications using old protocols and standards, respectively GIOP and CORBA, can be beneficial for the infosec community, since no many examples of vulnerabilities in such applications are available or published on the Internet.


Pwning a thin client in less than one minute, again!

Back in 2015, I have published a blog post titled "Pwning a thin client in less two minutes" which attracted a lot of curiosity from the Internet and which was also featured in the HACKADAY blog.

Today, together with Vincent Hutsebaut (@vhutsebaut), we are releasing a further technique to pwn the same thin client and get a root shell without authentication, in less than one minute!

The attack detailed below is a typical kiosk attack which consists in a local privilege escalation which affects different versions of HP Thin Pro OS (HP ThinPro 4.4, HP ThinPro 5.0, HP ThinPro 5.1, HP ThinPro 5.2, HP ThinPro 5.2.1, HP ThinPro 6.0, HP ThinPro 6.1).

The vulnerability (CVE-2016-2246) has been patched by HP and a technical bulletin has been published. HP stated that they have fixed the issue before our report was sent to them and were on the way to publish a security bulletin when we contacted them.

Since the patch is out, let's dive into the vulnerability, which is detailed ste…

Microsoft Windows PDF Library Information Disclosure Vulnerability - CVE-2016-3374 (MS16-115)

In the last year, as a personal research project, I started to look more into browsers and decided to fuzz some high-level targets, such as Edge and IE11, together with Steven Seeley (@steventseeley).

I have to admit that it is quite hard nowadays to approach this kind of research, especially with limited time and resources (just few virtual machines running at home…), but nevertheless it became an incredible learning experience.

Given our constraints, the fuzzing focus was to target other things than common targeted components, such as DOM, JavaScript and so on, so we decided to go for the PDF file format.

One of the interesting conditions that we found was the one that has just been patched by Microsoft and detailed in the MS16-115 security bulletin. The vulnerability is an out-of-bounds read which can lead to memory information disclosure.

The technical advisory can be found at Steven Seeley's web site: .

- Microsoft Sec…

TrendMicro ScanMail for Microsoft Exchange (SMEX) predictable session token - CVE-2015-3326

It's time for another advisory (CVE-2015-3326), a simple one, for a vulnerability which can be found quickly and trivially. For those of you who just want to give a glance at the post, I suggest to directly watch the picture which says it all!

The following vulnerability was discovered on TrendMicro SMEX (ScanMail for Microsoft Exchange) 10 SP2 but it affects other versions as well.

While surfing the SMEX web administrative interface using a web proxy, I have noticed something in the HTTP request - the session token itself and its format, a number.

After observing a significant number of logins, the session token was always represented with an number composed of minimum 4 digits and maximum 5 digits, as shown in the screen shot below:

Although the observed session tokens were never generated sequentially, the lack of a cryptographically strong PRNG for the session identifier, allows a malicious user to trivially guess the token. This attack can be easily automated.

For example, in…

Microsoft .NET MVC ReDoS (Denial of Service) Vulnerability - CVE-2015-2526 (MS15-101)

Microsoft released a security bulletin (MS15-101) describing a .NET MVC Denial of Service vulnerability (CVE-2015-2526) that I reported back in April. This blog post analyses the vulnerability in details, starting from the theory and then providing a PoC exploit against a MVC web application developed with Visual Studio 2013.
For those of you who want to see the bug, you can directly skip to the last part of this post or watch the video directly... ;-)

A bit of theory

The .NET framework (4.5 tested version) uses backtracking regular expression matcher when performing a match against an expression. Backtracking is based on the NFA (non-deterministic finite automata) algorithm engine which is designed to validate all input states. By providing an “evil” regex expression – an expression for which the engine can be forced to calculate an exponential number of states - it is possible to force the engine to calculate an exponential number of states, leading to a condition defined such as “ca…