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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 Interne...

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 i...

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:  http://srcincite.io/advisories/src-2016-0039/ . Refer...

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 ...

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 su...

Have you ever encountered a zero client or a thin client? It looks something like this... If yes, keep reading below, if not, then if you encounter one, you know what you can do if you read below... The model above is a T520, produced by HP - this model and other similar models are typically employed to support a medium/large VDI (Virtual Desktop Infrastructure) enterprise. These clients run a Linux-based HP ThinPro OS by default and I had a chance to play with image version T6X44017 in particular, which is fun to play with it, since you can get a root shell in a very short time without knowing any password... Normally, HP ThinPro OS interface is configured in a kiosk mode, as the concept of a thin/zero client is based on using a thick client to connect to another resource. For this purpose, a standard user does not need to authenticate to the thin client per se and would just need to perform a connection - e.g. VMware Horizon View. The user will eventually authenticat...