Nov 14 2017

Krebs on Security 2017-11-14 19:12:32

It’s Nov. 14 — the second Tuesday of the month (a.k.a. “Patch Tuesday) — and Adobe and Microsoft have issued gobs of security updates for their software. Microsoft’s 11 patch bundles fix more than four-dozen security holes in various Windows versions and Office products — including at least four serious flaws that were publicly disclosed prior to today. Meanwhile, Adobe’s got security updates available for a slew of titles, including Flash Player, Photoshop, Reader and Shockwave.

Four of the vulnerabilities Microsoft fixed today have public exploits, but they do not appear to be used in any active malware campaigns, according to Gill Langston at security vendor Qualys. Perhaps the two most serious flaws likely to impact Windows end users involve vulnerabilities in Microsoft browsers Internet Explorer and Edge.

Qualys’ Langston reminds us that on last Patch Tuesday, Microsoft quietly released the fix for CVE-2017-13080, widely known as the KRACK vulnerability in WPA2 wireless protocol, but did not make it known until a week later, when the vulnerability was publicly disclosed. Check out the Qualys blog and this post from Ivanti for more on this month’s patches from Redmond. Otherwise, visit Windows Update sometime soon (click the Start/Windows button, then type Windows Update).

Adobe issued patches to fix at least 62 security vulnerabilities in its products, including several critical bugs in Adobe Flash Player and Reader/Acrobat.  The Flash Player update brings the browser plugin to v. 27.0.0.187 on Windows, Mac, Linux and Chrome OS.

Windows users who browse the Web with anything other than Internet Explorer may need to apply the Flash patch twice, once with IE and again using the alternative browser (Firefox, Opera, e.g.).

Chrome and IE should auto-install the latest Flash version on browser restart (users may need to manually check for updates and/or restart the browser to get the latest Flash version). Chrome users may need to restart the browser to install or automatically download the latest version.

When in doubt, click the vertical three dot icon to the right of the URL bar, select “Help,” then “About Chrome”: If there is an update available, Chrome should install it then. Chrome will replace that three dot icon with an up-arrow inside of a circle when updates are waiting to be installed.

Standard disclaimer: Because Flash remains such a security risk, I continue to encourage readers to remove or hobble Flash Player unless and until it is needed for a specific site or purpose. More on that approach (as well as slightly less radical solutions ) can be found in A Month Without Adobe Flash Player. The short version is that you can probably get by without Flash installed and not miss it at all.

For readers still unwilling to cut the cord, there are half-measures that work almost as well. Fortunately, disabling Flash in Chrome is simple enough. Paste “chrome://settings/content” into a Chrome browser bar and then select “Flash” from the list of items. By default it should be set to “Ask first” before running Flash, although users also can disable Flash entirely here or whitelist and blacklist specific sites.

Another, perhaps less elegant, solution is to keep Flash installed in a browser that you don’t normally use, and then to only use that browser on sites that require it.

Oct 11 2017

Krebs on Security 2017-10-11 10:18:40

Microsoft on Tuesday released software updates to fix at least 62 security vulnerabilities in Windows, Office and other software. Two of those flaws were detailed publicly before yesterday’s patches were released, and one of them is already being exploited in active attacks, so attackers already have a head start.

brokenwindowsRoughly half of the flaws Microsoft addressed this week are in the code that makes up various versions of Windows, and 28 of them were labeled “critical” — meaning malware or malicious attackers could use the weaknesses to break into Windows computers remotely with no help from users.

One of the publicly disclosed Windows flaws (CVE-2017-8703) fixed in this batch is a problem with a feature only present in Windows 10 known as the Windows Subsystem for Linux, which allows Windows 10 users to run unmodified Linux binary files. Researchers at CheckPoint recently released some interesting research worth reading about how attackers might soon use this capability to bypass antivirus and other security solutions on Windows.

The bug quashed this week that’s being actively exploited resides in Microsoft Office (CVE-2017-11826), and Redmond says attackers could seize control over a vulnerable system just by convincing someone to open a booby-trapped Word file. Another Office vulnerability, (CVE-2017-11776), involves a flaw in Outlook’s ability to encrypt messages; SEC-Consult has more details on this bug.

Another critical flaw (CVE-2017-11779) addresses a scary vulnerability in the domain name system (DNS) component of Windows 8 and Windows Server 2012. According to research from Bishop Fox, the security firm credited with finding and reporting the bug, this flaw could be exploited quite easily to gain complete control over vulnerable systems if the attacker controls or compromises a local network (think Wi-Fi hotspot).

Normally, Adobe uses Microsoft’s Patch Tuesday (the second Tuesday of each month) to release its own fixes for Flash Player, Reader and other products. However, this time around the company has no security updates available. Adobe did release a new version of Flash that includes bug fixes (v. 27.0.0.159), but generally speaking only even-numbered Flash releases include security fixes.

For additional commentary on October’s bundle of updates from Microsoft, see these blogs from security vendors Ivanti and Qualys. For those looking for a straight-up list of which patches deserve priority, check out the always useful roundup from the SANS Internet Storm Center.

Sep 13 2017

Krebs on Security 2017-09-13 12:42:30

Adobe and Microsoft both on Tuesday released patches to plug critical security vulnerabilities in their products. Microsoft’s patch bundles fix close to 80 separate security problems in various versions of its Windows operating system and related software — including two vulnerabilities that already are being exploited in active attacks. Adobe’s new version of its Flash Player software tackles two flaws that malware or attackers could use to seize remote control over vulnerable computers with no help from users.

brokenwindows

Of the two zero-day flaws being fixed this week, the one in Microsoft’s ubiquitous .NET Framework (CVE-2017-8759) is perhaps the most concerning. Despite this flaw being actively exploited, it is somehow labeled by Microsoft as “important” rather than “critical” — the latter being the most dire designation.

More than two dozen flaws Microsoft remedied with this patch batch come with a “critical” warning, which means they could be exploited without any assistance from Windows users — save for perhaps browsing to a hacked or malicious Web site.

Regular readers here probably recall that I’ve often recommended installing .NET updates separately from any remaining Windows updates, mainly because in past instances in which I’ve experienced problems installing Windows updates, a .NET patch was usually involved.

For the most part, Microsoft now bundles all security updates together in one big patch ball for regular home users — no longer letting people choose which patches to install. One exception is patches for the .NET Framework, and I stand by my recommendation to install the patch roll-ups separately, reboot, and then tackle the .NET updates. Your mileage may vary.

Another vulnerability Microsoft fixed addresses “BlueBorne” (CVE-2017-8628), which is a flaw in the Bluetooth wireless data transmission standard that attackers could use to snarf data from Bluetooth-enabled devices that are physically nearby and with Bluetooth turned on.

For more on this month’s Patch Tuesday from Microsoft, check out Microsoft’s security update guide, as well as this blog from Ivanti (formerly Shavlik).

brokenflash-aAdobe’s newest Flash version — v. 27.0.0.130 for Windows, Mac and Linx systems — corrects two critical bugs in Flash. For those of you who still have and want Adobe Flash Player installed in a browser, it’s time to update and/or restart your browser.

Windows users who browse the Web with anything other than Internet Explorer may need to apply the Flash patch twice, once with IE and again using the alternative browser (Firefox, Opera, e.g.).

Chrome and IE should auto-install the latest Flash version on browser restart (users may need to manually check for updates and/or restart the browser to get the latest Flash version). Chrome users may need to restart the browser to install or automatically download the latest version. When in doubt, click the vertical three dot icon to the right of the URL bar, select “Help,” then “About Chrome”: If there is an update available, Chrome should install it then. Chrome will replace that three dot icon with an up-arrow inside of a circle when updates are ready to install).

Better yet, consider removing or at least hobbling Flash Player, which is a perennial target of malware attacks. Most sites have moved away from requiring Flash, and Adobe itself is sunsetting this product (albeit not for another long two more years).

Windows users can get rid of Flash through the Add/Remove Programs menu, unless they’re using Chrome, which bundles its own version of Flash Player. To get to the Flash settings page, type or cut and paste “chrome://settings/content” into the address bar, and click on the Flash result.

Aug 02 2017

Krebs on Security 2017-08-02 12:17:05

Adobe last week detailed plans to retire its Flash Player software, a cross-platform browser plugin so powerful and so packed with security holes that it has become the favorite target of malware developers. To help eradicate this ubiquitous liability, Adobe is enlisting the help of Apple, Facebook, Google, Microsoft and Mozilla. But don’t break out the bubbly just yet: Adobe says Flash won’t be put down officially until 2020.

brokenflash-aIn a blog post about the move, Adobe said more sites are turning away from proprietary code like Flash toward open standards like HTML5, WebGL and WebAssembly, and that these components now provide many of the capabilities and functionalities that plugins pioneered.

“Over time, we’ve seen helper apps evolve to become plugins, and more recently, have seen many of these plugin capabilities get incorporated into open web standards,” Adobe said. “Today, most browser vendors are integrating capabilities once provided by plugins directly into browsers and deprecating plugins.”

It’s remarkable how quickly Flash has seen a decline in both use and favor, particularly among the top browser makers. Just three years ago, at least 80 percent of desktop Chrome users visited a site with Flash each day, according to Google. Today, usage of Flash among Chrome users stands at just 17 percent and continues to decline (see Google graphic below).

For Mac users, the turning away from Flash began in 2010, when Apple co-founder Steve Jobs famously penned his “Thoughts on Flash” memo that outlined the reasons why the technology would not be allowed on the company’s iOS products. Apple stopped pre-installing the plugin that same year.

The percentage of Chrome users over time that have used Flash on a Web site. Image: Google.

The percentage of Chrome users over time that have used Flash on a Web site. Image: Google.

“Today, if users install Flash, it remains off by default,” a post by Apple’s WebKit Team explains. “Safari requires explicit approval on each website before running the Flash plugin.”

Mozilla said that starting this month Firefox users will choose which websites are able to run the Flash plugin.

“Flash will be disabled by default for most users in 2019, and only users running the Firefox Extended Support Release will be able to continue using Flash through the final end-of-life at the end of 2020,” writes Benjamin Smedberg for Mozilla. “In order to preserve user security, once Flash is no longer supported by Adobe security patches, no version of Firefox will load the plugin.”

Facebook has long hosted plenty of games that invoke Flash, but over time more Facebook apps and games turned to HTML5, the company said.

“Today, more than 200 HTML5 games are live on our platform, most of which launched within the last year,” wrote Facebook’s Jakub Pudelek. “Many of the largest developers on the platform…migrated at least one Flash game to HTML5 on the Facebook platform with minimal impact to their existing customers.”

Finally, Microsoft said it has begun phasing out Flash from Microsoft Edge and Internet Explorer, culminating in the removal of Flash from Windows entirely by the end of 2020. For now, Microsoft Edge, the default browser on newer versions of Windows, will continue to ask users for permission to run Flash on most sites the first time the site is visited, remembering the user’s preference on any subsequent visits.

By mid- to late 2018, Microsoft says, Edge will require permission for Flash to be run each browser session. But by mid 2018, Microsoft will disable Flash by default in both Edge and Internet Explorer. Read more about Microsoft’s timeline for Flash elimination here.

For years, unpatched vulnerabilities in Flash plugins have been the top moneymaker for users of various commercial “exploit kits,” crimeware designed to be stitched into the fabric of hacked or malicious sites and exploit browser plugin flaws.

An analysis of exploit kit activity  by Arlington, Va.-based security firm Recorded Future showed that Flash Player vulnerabilities provided six of the top 10 vulnerabilities used by exploit kits in 2016 [full disclosure: Recorded Future is an advertiser on this blog].

Image: Recorded Future

Image: Recorded Future

I look forward to a time when Flash Player is in the rearview mirror entirely. Until then, KrebsOnSecurity will continue to call attention to new security updates for Flash Player and other widely used Adobe products.

Even so, I’ll also continue to encourage readers to remove or hobble Flash Player unless and until it is needed for a specific site or purpose. More on that approach (as well as slightly less radical solutions ) can be found in A Month Without Adobe Flash Player. The short version is that you can probably get by without Flash installed and not miss it at all.

For readers still unwilling to cut the cord, there are half-measures that work almost as well. Fortunately, disabling Flash in Chrome is simple enough. Paste “chrome://settings/content” into a Chrome browser bar and then select “Flash” from the list of items. By default it should be set to “Ask first” before running Flash, although users also can disable Flash entirely here or whitelist and blacklist specific sites.

Another, perhaps less elegant, solution is to keep Flash installed in a browser that you don’t normally use, and then to only use that browser on sites that require it.