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How to break out of restricted shells with tcpdump

During security assessments we sometimes obtain access to a restricted shell on a target system. To advance further and gain complete control of the system, the next step is usually to break out of this shell. If the restricted shell provides access to certain system binaries, these binaries can often be exploited to perform such a break out. Here we would like to show an interesting example of such a break out by using the tcpdump binary. Continue reading “How to break out of restricted shells with tcpdump”

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Multiple Vulnerabilities in innovaphone VoIP Products Fixed

Dear all,

innovaphone fixed several vulnerabilities in two VoIP products that we disclosed a while ago. The affected products are the Linux Application Platform and the IPVA. Unfortunately, the release notes are not public (yet?) and the vendor does not include information about the vulnerabilities for the Linux Application Platform. Therefore, we decided to publish some more technical details for the issues. Continue reading “Multiple Vulnerabilities in innovaphone VoIP Products Fixed”

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Breaking

On the insecurity of math.random and it’s siblings

During code reviews we often see developers using weak RNGs like math.random() to generate cryptographic secrets. We think it is commonly known that weak random number generators (RNG) must not be used for any kind of secret and recommend using secure alternatives. I explicitly did not state a specific language yet, because basically every language offers both weak and strong RNGs.

So I asked myself: What if I use a weak RNG to generate a secret? Is it possible to recover the secret from some derived value, like a hash?

Continue reading “On the insecurity of math.random and it’s siblings”

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Breaking

Plume Twitter Client URL Spoofing

It is possible to spoof the URLs that Plume will open to arbitrary locations because of how Plume parses URLs. The preview of an URL in a tweet will show the complete (at least the host name and the first few chars of the URL) but shortened URL. However, if the URL contains a semicolon (;) the URL that will be opened is the part after the semicolon. Continue reading “Plume Twitter Client URL Spoofing”

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Pidgin, Word Documents, my Clipboard and I

Lately, I’ve experienced some weird Pidgin crashes when I was copy&pasting into chat windows. The strange part was: I didn’t even know what triggered the crash because I actually didn’t know what was in my clipboard at this exact point. This is a quick write-up of how I investigated the issue and some interesting properties I found out about clipboards.

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Multiple Vulnerabilities in Nexus Repository Manager

Recently, we identified security issues in the Nexus Repository Manager software developed by Sonatype. The tested versions were OSS 3.12.1-01 and OSS 3.13.1-01.

The following issues could be identified:

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Vulnerabilities in Sitefinity WCMS – A Success Story of a Responsible Disclosure Process

Preface

For those who never heard of Sitefinity before, it is an ASP.NET-based Web Content Management System (WCMS), which is used to deploy and manage applications as other CMS‘s do. A bitter quick glance at Sitefinity and its advantages can be found in this overview.

Delving into the core of this blog post, recently I had the opportunity to look at Sitefinity WCMS in which I found two reflected Cross Site Scripting (XSS) (CVE-2018-17053 and CVE-2018-17056), a stored XSS (CVE-2018-17054) and an arbitrary file upload (CVE-2018-17055) vulnerabilities.

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Spraying arbitrary objects into the non-paged pool

Recently, I had some time to play around with HEVD [1], an extremly vulnerable Windows driver available for 32-bit and 64-bit systems.

Since exploits for all vulnerabilities of the 32-bit variant are publically available, I was wondering why this is not the case for the 64-bit version, especially for the pool corruption and UAF vulnerabilities.

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