Building

Reversing C++ Without Getting a Heart Attack – DEvirtualize VIrtual Calls With Devi

TLDR: This blogpost presents devi, a tool that can help you devirtualize virtual calls in C++ binaries. It uses Frida to trace the execution of a binary and uncover the call sources and destinations of virtual calls. The collected information can then be viewed in IDA Pro, Binary Ninja, or Ghidra. The plugin adds the respective control-flow edges allowing further analysis (using different plugins) or simply providing more comfort when analyzing C++ binaries.

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Misc

Apps on Prescription?! – Perspectives on Digital Health Applications (DiGA)

Some time ago, we carried out an evaluation of the Digital Health Applications Ordinance (Digitale-Gesundheitsanwendungen-Verordnung, DiGAV) for the Federal Chamber of Psychotherapists in Germany (Bundespsychotherapeutenkammer, BPtK) focusing on the security of digital health applications, often referred to as apps on prescription.

The audit was intended to determine to which extent security guidelines, security objectives, and best practices are adhered to by the requirements formulated by the ordinance, thus enabling the foundations to securely operate digital health applications. The main subject of the examination is whether requirements, including procedural requirements defined in the ordinance are sufficient to ensure security of digital health applications. The examination has shown that the requirements can be seen as positive. However, in order to be able to make reliable statements about the IT security of digital healthcare applications, further details and mechanisms should be clarified within the ordinance, which I would like to present in the following.

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Misc

OpenSIS Vulnerabilities

OpenSIS is an open source student information system. Recently, it was affected by several vulnerabilities such as SQL injections, local file inclusions and incorrect access controls (CVE-2020-13380, CVE-2020-13381, CVE-2020-13382, CVE-2020-13383). That is why I got interested and also had a quick look at the application.

As part of this investigation, I discovered two vulnerabilities, an XSS vulnerability (CVE-2020-27409) in the file SideForStudent.php that got quickly fixed after being reported (see commit edca085 for the details; the commit is included in release v7.5) and some incorrect (i.e. non-existent) access controls for the password change functionality (CVE-2020-27408). In this blog post, I would like to focus on the second vulnerability and describe the tedious disclosure process that – in the end – lead to nothing but the implementation of some ineffective obfuscation mechanism.
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Breaking

ERNW White Paper 69 – Safety Impact of Vulnerabilities in Insulin Pumps

With this blog post I am pleased to announce the publication of a new ERNW White Paper [1]. The paper is about severe vulnerabilities in an insulin pump we assessed during project ManiMed and we are proud to publish this subset of the results today.

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Building, Misc

How can data from fitness trackers be obtained and analyzed with a forensic approach?

The use of Internet of Things devices is continuously increasing: People buy devices, such as smart assistants, to make their lives more comfortable or fitness trackers to assess sports activities. According to the Pew Research Center [1], every fifth American wears a device to track their fitness. In Germany, the number increases likewise. The increasing number of fitness trackers in use can also be seen in criminal proceedings, as there exist more and more cases where these devices provide evidence.

Which useful evidential information fitness trackers collect and how to analyze them forensically was part of a paper that we presented at WACCO 2020 this year [2]. The goal was to develop an open source program to support investigators analyzing data that fitness trackers provide and to give a general approach on how to analyze fitness trackers.

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Misc

Puppet Assessment Techniques

Hardening guides for different systems that can be managed by Puppet are easy to find, but not the guides for hardening Puppet itself.

The enterprise software configuration management (SCM) tool Puppet is valued by many SysAdmins and DevOps, e.g. at Google, for scalable, continuous and secure deployment of application server configuration files across large heterogeneous system landscapes and increasingly also as “end-to-end” compliance solution.

Disclaimer:
This blog post does not present anything new about Puppet security, but aims to raise security awareness and summarize useful attack and audit techniques for an internal black and whitebox infrastructure assessment of a Puppet Enterprise landscape.
Most information in this post were collected during and based-on a time-limited graybox Puppet landscape assessment (Puppet Enterprise version 6.4.0, on RHEL7).
Hence, there is no claim for completeness and the post shall not be considered as a fully fledged Puppet hardening guide.

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Misc

Java Buffer Overflow with ByteBuffer (CVE-2020-2803) and Mutable MethodType (CVE-2020-2805) Sandbox Escapes

Years ago, Java could be used on websites trough applets. To make these applets secure and not let them access files or do other dangerous stuff, Java introduced the SecurityManager. Before some action was performed, the SecurityManager was asked if the code is privileged to perform this action. However, since the SecurityManager lives in the same running program and can be accessed via System.getSecurityManager(), there existed some ways to remove it. Continue reading “Java Buffer Overflow with ByteBuffer (CVE-2020-2803) and Mutable MethodType (CVE-2020-2805) Sandbox Escapes”

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Misc

Security Advisories for Nagios XI

In June 2020 we reported three vulnerabilities in Nagios XI 5.7.1 to the vendor.
The following CVE IDs were assigned to the issues :

  •  CVE-2020-15901: Command Injection in Nagios XI web interface (RCE)
  •  CVE-2020-15902: Cross Site Scripting (XSS)
  •  CVE-2020-15903: Reserved, details will be given on vendor fix

CVE-2020-15901 and CVE-2020-15902 have meanwhile been fixed in version 5.7.2 according to the changelog on the Nagios website (https://www.nagios.com/downloads/nagios-xi/change-log/). CVE-2020-15903 is currently being worked on by the vendor and will probably be fixed in the near future.

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