Category Archives: Security

aka infosec

Firefox 40 improves add-on security

The newest Firefox is version 40, and as usual there was no proper announcement. There’s a post on the Mozilla blog that gets into the details of version 40’s security improvements, but it never mentions the version. The release notes provide additional details. Here are some of the more notable changes:

  • Improvements to Windows 10 support, including workarounds for the way Microsoft messes up default browser settings
  • Add-on certification: non-certified add-ons will be disabled by default
  • Improvements to visual style: for example, the ‘close’ button on tabs is now larger
  • Expanded malware protection, which warns users about to visit sites that are flagged by Google’s Safe Browsing Service
  • Smoother animation and scrolling for Windows
  • Improvements to JPEG image handling
  • At least fourteen security fixes

Patch Tuesday for August

Ah, Patch Tuesday. Of all the tasks we have to perform, there’s nothing quite like it: it’s both tedious and critically important. I’m starting to consider enabling automatic updates, but given Murphy’s Law, no doubt the moment I do that, Microsoft will issue a catastrophic update.

This month we have fourteen updates from Microsoft, affecting the usual culprits (Windows, Internet Explorer, Office, Silverlight, .NET), plus a few new ones: Lync and Edge, the new web browser in Windows 10. Four of the updates are flagged as critical. The updates address a total of 58 vulnerabilities. The update for Silverlight brings its version to 5.1.40728.0. Several of the updates apply to Windows 10. One of the updates addresses a nasty bug that could allow an attacker to execute malicious code from a USB thumb drive.

Adobe is once again tagging along this month, releasing a new version of Flash (18.0.0.232) that addresses a whopping thirty-four vulnerabilities. Needless to say, you should install the new version as soon as possible if you still use Flash in any web browser. Internet Explorer 10 and 11 in Windows 8.x will receive the Flash update via Windows Update, as will the new Edge browser in Windows 10. Chrome will update itself to use the new version.

Critical vulnerability in Firefox’s PDF viewer

Firefox has had its own internal PDF viewer for a while now, and it’s enabled by default. When you click on a PDF file link in Firefox, it will do one of the following: a) open with Firefox’s internal viewer; b) open with a PDF viewer plugin such as Adobe’s Reader plugin; or c) download and open with an external viewer. Unfortunately, PDF files can also be embedded on web pages, in which case there’s no need to click on anything to view them; merely visiting a web site with an embedded PDF will show the file’s contents. Worse still, some advertising platforms serve ads in the form of PDF files.

Now comes news that a newly-discovered vulnerability in Firefox’s internal PDF viewer is being actively exploited on at least one advertising network, and that malware-containing PDF ads were recently observed on a Russian news site.

Mozilla confirmed the bug and quickly released Firefox 39.0.3 to address it. All users are strongly encouraged to update Firefox as soon as possible.

But there’s more bad news. There’s no way to know whether this vulnerability has been exploited elsewhere on the web. There’s no reason to assume that only one Russian news site was affected, or that infected ads haven’t already appeared on other ad networks and web sites. If you use Firefox with the internal PDF viewer enabled, there’s a chance your computer ran a malicious script at some point. If you run a script blocker like Noscript, and you haven’t altered its default behaviour, you were probably protected.

The only known instance of a malicious script that exploits this vulnerability looks for configuration files related to Subversion, Pidgin, Filezilla, and other FTP applications on Windows systems. If you have any passwords stored in these configuration files, you should consider changing those passwords.

You might also want to consider disabling Firefox’s built-in PDF viewer. To do that, enter ‘about:config’ in the address bar. You’ll see a warning; confirm that you want to proceed by clicking the “I’ll be careful” button. In the Search box, enter ‘pdfjs.disabled’. One setting should appear in the list below. If the setting is currently ‘false’, double-click it to change it to ‘true’. This will prevent embedded PDFs from being shown on web pages.

WordPress 4.2.4 security release

The latest WordPress release resolves several security issues, including an SQL injection that could be used to compromise a site.

The WordPress 4.2.4 release notes have additional details.

WordPress sites with the auto-update mechanism enabled should be updated automatically in the next day or so, but if you don’t want to wait, you can install the update manually from the site’s dashboard.

July security roundup

Flash improvements

Adobe is trying desperately to keep Flash viable. In July, they announced structural changes that are expected to strengthen Flash’s overall security. The changes are so far only available in the most recent versions of Chrome, but they are expected to find their way into the other major browsers in August.

Asprox botnet status

There’s an interesting (though technical) overview of recent changes in the behaviour of the Asprox botnet over on the SANS Handler’s Diary. Apparently the botnet is no longer sending malware attachments, and is instead sending pornography and diet-related spam. Comparing my inbox contents with the samples in the linked article, it looks like most of the spam I currently receive is thanks to Asprox. Hopefully Asprox will be targeted by the anti-botnet heavy hitters in the near future.

Flaw in BIND could cause widespread issues

BIND is one of the most common pieces of software on Internet-facing servers. It translates human-readable addresses like ‘boot13.com’ into IP addresses. A bug in version 9 of BIND causes it to crash when a specially-crafted packet is sent to it. Attackers could exploit this bug to execute an effective Denial of Service (DoS) attack against a server running BIND9. Patches have been created and distributed, but any remaining unpatched servers are likely to be identified and attacked in the coming months. Update 2015Aug05: As expected, this bug is now being actively exploited.

Mobile versions of IE are vulnerable

Current, patched versions of Internet Explorer running on mobile devices were recently reported to have four flaws that could allow attackers to run code remotely. Exploits were published, although none have yet been seen in the wild. The vulnerabilities were disclosed by the HP/TippingPoint researchers who discovered them, six months after they privately reported them to Microsoft. Microsoft has yet to patch these vulnerabilities; they apparently feel that vulnerabilities are too difficult to exploit for them to be dangerous.

Stagefright vulnerability on Android devices

A flaw in Stagefright, a core Android software library that processes certain types of media, makes almost all Android phones and tablets vulnerable. The flaw can be exploited as easily as sending a specially-crafted text (MMS) message to a phone, but also by tricking the user into visiting a specific web site. Successful attackers can then access user data and execute code remotely. Unfortunately for users, it’s up to individual manufacturers to develop and provide patches, and this process may take months in some cases. There’s not much users can do to mitigate this problem until patches arrive. Update 2015Aug05: Google is working with its partners to push updates to affected mobile devices.

Mediaserver vulnerability on Android devices

More bad news for Android users: the mediaserver service apparently has difficulty processing MKV media files, and can render a device unusable when it encounters one on a malicious web site. In most cases, the device can be brought back to life by powering it down and back up again.

Android spyware toolkit widely available

And the hits just keep on coming for Android devices. Among the information revealed in the recent Hacking Team breach was the source code for an advanced Android spyware toolkit called RCSAndroid. Like everything else taken from Hacking Team’s systems, this has now been published, and no doubt malicious persons are working on ways to use the toolkit. There’s no easy way to protect yourself from this toolkit, aside from keeping your device up to date with patches. From Trend Micro: “Mobile users are called on to be on top of this news and be on guard for signs of monitoring. Some indicators may come in the form of peculiar behavior such as unexpected rebooting, finding unfamiliar apps installed, or instant messaging apps suddenly freezing.

Microsoft issues special update for critical Windows vulnerability

An update for a vulnerability in the Microsoft Font Driver – present in all supported versions of Windows – was released yesterday by Microsoft. Normally, updates like this are released as part of the monthly Patch Tuesday process, but Microsoft evidently decided that this vulnerability was serious enough to warrant this ‘out of band’ update.

Windows systems with Automatic Updates enabled will receive this update automatically. All other systems should be updated via Windows Update as soon as possible.

Java 8 Update 51 fixes 25 vulnerabilities

Yesterday, Oracle released a huge set of updates for all its products, in the July installment of their quarterly Critical Patch Update.

Included in the updates is a new version of Java, version 8 update 51. The new Java includes fixes for at least 25 security vulnerabilities. Anyone who uses a web browser with Java enabled should install the new version as soon as possible. According to Oracle, exploits for at least one of the Java vulnerabilities have been seen in the wild.

Patch Tuesday for July 2015

This month there are fourteen bulletins from Microsoft, with associated updates affecting Windows, Internet Explorer, Office and SQL Server. Four of the updates are flagged as Critical. The updates address at least fifty-nine vulnerabilities.

From Adobe, there are updates for Flash (see previous post), Reader/Acrobat (version 2015.008.20082) and Shockwave (version 12.1.9.159).

So, although installing updates on computers is probably not anyone’s idea of summer fun, let’s all try to keep our sense of humour as we once again work through the monthly update grind. Enjoy!

Update 2015Jul16: This month’s Microsoft updates address three vulnerabilities (two in Internet Explorer) exposed in the recent Hacker Team leak.