Daily Archives: November 24, 2015

VMware Security Updates Address Information Disclosure Vulnerability

In the middle of last week VMware issued security updates for the following products:

VMware vCenter Server
VMware vCloud Director
VMware Horizon View

These updates address 1x information disclosure security vulnerability (CVE, defined). This vulnerability was responsibly disclosed (defined) by security researcher Matthias Kaiser from Code White.

Why Should This Issue Be Considered Important?
Since multiple VMware products have this vulnerability which could be used to leak the contents of sensitive files on your network, this issue should be patched as soon as possible.

This issue occurs since the XML (defined) parser (a program that analyzes data in a structured manner in order to create meaning from it) contained within Apache Flex BlazeDS 4.7.0 (and earlier) when passed a specifically crafted request parameter (a value to be placed into a program before it carries out a task) could be used to access the contents of a file on your network.

An example of the path (a means of locating/looking up a file starting from the root (beginning) of a file system and progressing towards the desired file) to such a file is shown on the final line of the first code snippet (paragraph) with the title “Disclosing /etc/passwd or other targeted files” of this article from OWASP.

Where etc/passwd is the password file of a Linux/Unix system that stores hashed (defined) user account credentials. Such an attack is called an XML External Entity (XXE) attack (defined). Most importantly, Code White within a blog post discussing this issue describe the issue as easy for an attacker to exploit.

How Can I Protect Myself From This Issue?
VMware have released updates to resolve this issue within the affected products. Please refer to VMware’s security advisory to download the necessary updates.

OWASP also list best practices to avoid XXE attacks in general with examples for many popular programming languages.

Thank you.

Wireshark Releases Major New Version

On Wednesday of last week, the Wireshark Foundation released a major new update for their very popular open source packet analyzer, Wireshark. This project has now reached version 2.0.0.

While this version does not include any security related fixes it does include a large amount of general bug fixes and introduces a new look to the program. A full list of changes is available here in the release notes. A summary of changes can be found in Gerald Combs’ blog post. A video introduction to this version is available here.

As mentioned in the release notes, the traditional look and feel (interface) of previous 1.12 (and earlier versions) will be removed in version 2.2. Since it is likely that future security fixes will only be made available for version 2.0.0 and newer, if you use Wireshark you should begin testing this new version before more widely using it for day to day activities.

For Linux distributions this update can be obtained using the operating systems standard package manager (if the latest version is not installed automatically you can instead compile the source code). This forum thread and this forum thread may also be helpful to you with installing Wireshark on your Linux based system.

For Mac OS X and Windows, the update is available within the downloads section of the Wireshark website. In addition, a detailed FAQ for Wireshark is available here.

As always, if Wireshark is installed on a critical production system or systems that contain your critical data, please back up your data before installing this update in order to prevent data loss in the rare event that an update causes unexpected issues.

Thank you.

Microsoft Updates Edge Browser To Harden Against DLL Injection

On the 12th of November Microsoft began rolling out Windows 10 Build 10586 (also known as Version 1511). This was the first major update made available for Windows 10. Included in this update was an improved version of Microsoft Edge, the default browser of Windows 10.

For most consumers, this update will be delivered automatically to their PCs. For businesses and large organizations using the new Windows Update for Business they should be able to choose a time when they wish to deploy this update more widely to the company’s employees.

What’s The Main Security Improvement in This Update?
In the updated version of Microsoft Edge, known as EdgeHTML 13, DLLs (Dynamic Link Libraries, defined) are no longer permitted to load within Edge. DLLs are loaded into a Windows application using a technique known as DLL injection. The technique of DLL injection is explained in more detail here and here. It is this technique that Edge has been hardened against to prevent it succeeding.

Why Was This Change Made?
If an unauthorized DLL is loaded into a web browser, it can do such things as displaying un-wanted adverts (such as the type previously discussed by Google) or installing unnecessary toolbars that may attempt to re-direct your web searches from your preferred search engine to another search engine in order to benefit from increased usage (and possibly increased revenue when adverts are displayed among those search results). Such unwanted adverts and/or toolbars annoy and distract users and make their web browser less user friendly.

If I’m a Microsoft Edge user, how will this benefit me?
If you like using Microsoft Edge on Windows 10, this change will mean that it will be harder for adware and malware to be loaded into your browser either for malicious purposes or to simply display adverts. This means that your web browser is more likely to work the way you prefer and you can simply concentrate on achieving what you would like to do.

I welcome this change which makes every day browsing for Microsoft Edge users safer. Thank you.