Mark J Cox

Enterprise Linux 6.3 to 6.4 risk report

Wed, 27 Feb 2013 13:03:00 GMT

You can read my Enterprise Linux 6.3 to 6.4 risk report on the Red Hat Security Blog.

"for all packages, from release of 6.3 up to and including 6.4, we shipped 108 advisories to address 311 vulnerabilities. 18 advisories were rated critical, 28 were important, and the remaining 62 were moderate and low."
"Updates to correct 77 of the 78 critical vulnerabilities were available via Red Hat Network either the same day or the next calendar day after the issues were public. The other one was in OpenJDK 1.60 where the update took 4 calendar days (over a weekend)."

And if you are interested in how the figures were calculated, here is the working out:

Note that we can't just use a date range because we've pushed some RHSA the weeks before 6.4 that were not included in the 6.4 spin. These issues will get included when we do the 6.4 to 6.5 report (as anyone installing 6.4 will have got them when they first updated).
So just after 6.4 before anything else was pushed that day:
** Product: Red Hat Enterprise Linux 6 server (all packages)
** Dates: 20101110 - 20130221 (835 days)
** 397 advisories (C=55 I=109 L=47 M=186 )
** 1151 vulnerabilities (C=198 I=185 L=279 M=489 )

** Product: Red Hat Enterprise Linux 6 Server (default installation packages)
** Dates: 20101110 - 20130221 (835 days)
** 177 advisories (C=11 I=71 L=19 M=76 )
** 579 vulnerabilities (C=35 I=133 L=159 M=252 )
And we need to exclude errata released before 2013-02-21 but not in 6.4:
RHSA-2013:0273 [critical, default]
RHSA-2013:0275 [important, not default]
RHSA-2013:0272 [critical, not default]
RHSA-2013:0271 [critical, not default]
RHSA-2013:0270 [moderate, not default]
RHSA-2013:0269 [moderate, not default]
RHSA-2013:0250 [moderate, default]
RHSA-2013:0247 [important, not default]
RHSA-2013:0245 [critical, default]
RHSA-2013:0219 [moderate, default]
RHSA-2013:0216 [important, default]

Default vulns from above: critical:12 important:2 moderate:16 low:3
Non-Default vulns from above: critical:4 important:2 moderate:5 low:0
This gives us "Fixed between GA and 6.4 iso":
** Product: Red Hat Enterprise Linux 6 server (all packages)
** Dates: 20101110 - 20130221 (835 days)
** 386 advisories (C=51 I=106 L=47 M=182 )
** 1107 vulnerabilities (C=182 I=181 L=276 M=468 )

** Product: Red Hat Enterprise Linux 6 Server (default installation packages)
** Dates: 20101110 - 20130221 (835 days)
** 172 advisories (C=9 I=70 L=19 M=74 )
** 546 vulnerabilities (C=23 I=131 L=156 M=236 )
And taken from the last report "Fixed between GA and 6.3 iso":
** Product: Red Hat Enterprise Linux 6 server (all packages)
** Dates: 20101110 - 20120620 (589 days)
** 278 advisories (C=33 I=78 L=31 M=136 )
** 796 vulnerabilities (C=104 I=140 L=196 M=356 )

** Product: Red Hat Enterprise Linux 6 Server (default installation packages)
** Dates: 20101110 - 20120620 (589 days)
** 134 advisories (C=6 I=56 L=15 M=57 )
** 438 vulnerabilities (C=16 I=110 L=126 M=186 )
Therefore between 6.3 iso and 6.4 iso:
** Product: Red Hat Enterprise Linux 6 server (all packages)
** Dates: 20120621 - 20130221 (246 days)
** 108 advisories (C=18 I=28 L=16 M=46 )
** 311 vulnerabilities (C=78 I=41 L=80 M=112 )

** Product: Red Hat Enterprise Linux 6 Server (default installation packages)
** Dates: 20120621 - 20130221 (246 days)
** 38 advisories (C=3 I=14 L=4 M=17 )
** 108 vulnerabilities (C=7 I=21 L=30 M=50 )
Note: although we have 3 default criticals, they are in openjdk-1.6.0, but we only call Java issues critical if they can be exploited via a browser, and in RHEL6 the Java browser plugin is in the icedtea-web package, which isn't a default package. So that means on a default install you don't get Java plugins running in your browser, so really these are not default criticals in RHEL6 default at all.

OpenShift, perl, YouTube API

Tue, 09 Oct 2012 20:25:00 GMT

My wife is part of a competition to be the next face representing her college; with the final number of positive 'likes' on YouTube videos determining the winners. I thought it would be neat to create a scoreboard to track her progress, but also to learn how to use OpenShift all in one. It took me longer to write this blog than to write the code and deploy it live!

After creating an account on Red Hat OpenShift I created a new app based on perl and added a cron container so we can run our script every few minutes (to stop overloading the YouTube API if the site gets popular):

rhc-create-app -a fomc -t perl-5.10
rhc-ctl-app -a fomc -e add-cron-1.4
cd fomc

That was all the configuration needed, the 'fomc' directory is populated with everything you need. OpenShift when you deploy your app, figures out your perl dependencies and grabs and builds them for you, so no messing around needing root or even logging into the host.

By default the file perl/index.pl will get served, but since we're going to cache the output from the script let's make it a html file index. To do this simply add to the existing perl/.htaccess file:

DirectoryIndex index.html

I wrote this quick perl program to query the YouTube API and do a simplistic HTML page of the number of likes for each of the videos in the playlist, and placed it in the main directory as youtube.pl. Now to get it created every ten minutes we use the cron container by creating a file .openshift/cron/minutely/perljob with the contents:

#!/bin/bash
MIN=`date +%M`
if [ $((${MIN#0} % 10)) == 0 ]; then
    perl ${OPENSHIFT_REPO_DIR}/youtube.pl > ${OPENSHIFT_REPO_DIR}/index.html
    mv -f ${OPENSHIFT_REPO_DIR}/index.html ${OPENSHIFT_REPO_DIR}/perl/index.html
fi

The cron job is run every minute, but the "modulus 10" ensures we only run the perl script once every 10 minutes. We use an intermediate file so that anyone visiting the site during the time it takes to create the file doesn't get a blank page. Finally we want to make sure that we don't have to wait ten minutes for the file to be created when we push the app, and give people the ability to see the source, so we create .openshift/action_hooks/post_deploy with the contents:

cp ${OPENSHIFT_REPO_DIR}/youtube.pl ${OPENSHIFT_REPO_DIR}/perl/youtubepl.txt
perl ${OPENSHIFT_REPO_DIR}/youtube.pl > ${OPENSHIFT_REPO_DIR}/perl/index.html

And that's it. Just run

git add .
git commit -a -m 'first app'
git push

And the app is up and running; here it is: http://fomc-esoom.rhcloud.com/. If this blog was useful (blatent plug!) please click on "Tracy Cox", make sure you're logged in, and click "like" ;)

Enterprise Linux 6.2 to 6.3 risk report

Wed, 03 Oct 2012 15:16:00 GMT

You can read my Enterprise Linux 6.2 to 6.3 risk report on the Red Hat Security Blog.

"for all packages, from release of 6.2 up to and including 6.3, we shipped 88 advisories to address 233 vulnerabilities. 15 advisories were rated critical, 23 were important, and the remaining 50 were moderate and low."
"Updates to correct 34 of the 36 critical vulnerabilities were available via Red Hat Network either the same day or the next calendar day after the issues were public. The Kerberos telnet flaw was fixed in 2 calendar days as the issue was published on Christmas day. The second PHP flaw took 4 calendar days (over a weekend) as the initial fix released upstream was incomplete."

And if you are interested in how the figures were calculated, as always view the source of this blog entry.

Fedora or Android?

Fri, 28 Sep 2012 14:48:00 GMT

For a two day trip I decided to test using my Android tablet instead of also taking a laptop, and it worked out okay for the most part.

I was booked to go to Red Hat HQ in Raleigh, NC at the start of August for a two-day business trip, well more accurately two-days in the office and another two-days of travelling. I'd usually take my trusty ThinkPad x201 on the trip with me, it's small and light, but it's battery life isn't so great anymore. Earlier this year I'd bought an Android tablet, an ASUS Transformer Prime which with a long battery life would be perfect for movies, but could it replace my ThinkPad completely and save me travelling with two devices? I worked through my requirements and it seemed plausible in theory, so here is how it stacked up in practice:

Connectivity. In the UK you can only buy the Prime with the keyboard dock, the keyboard dock is great. The in-built wifi was okay for the airport, hotel, and office. I carry a USB network adapter anyway just in case the hotel has a physical connection. The wifi signal on the Prime is terrible compared to other things (like a phone) though, so be prepared to walk around a bit to the best signal. Partial Win.
In flight entertainment. I wanted something to watch movies (as US Airways transatlantic don't yet have seat-back video, really!). The large internal memory meant I could store a few films in decent quality to watch and battery life wasn't a problem. I'd used the tablet continously (without wifi) with the keyboard connected for 6 hours and wasn't even down to 50% battery. Although hardware decoding of videos was a bit hit-and-miss, and after trying a dozen apps only "BS Player" seemed to do a reasonable job. A couple of the movies I'd brought had low audio and I couldn't figure out a way to boost it enough to hear over the noise of the plane, even with decent in-ear noise blocking headphones. Having the keyboard dock helped considerably as with the tablet on the tray-table I could set a decent angle to watch a movie. Win.
Reading material. I had a few papers and magazines to read which I'd preloaded onto the tablet in PDF format. The Adobe PDF viewer is acceptable, but it seems a little sluggish for something running on a quad-core processor, and the screen resolution isn't really good enough for magazines. The new Transformer Infinity would help here. Partial Win.
Keeping in touch with home. The standard Android GMail app and Facebook app are okay, and I was able to use GMail talk to have video chats with my family from both the hotel and office. Win.
Working. With just a couple days away I figured all that was needed was the ability to read and send email and browse intranet internal web pages. The standard VPN client on the Prime worked perfectly, and along with the Firefox beta app gave me perfect access to internal sites. For email I prefer command-line text-window clients anyway, so I just needed to be able to connect to a work machine. "Connectbot" on Android works well enough for ssh, and there are a few forked versions you can get that work with the Prime keyboard. The AndChat app works for irc. Win.
Presentations. I was giving a presentation at a meeting, but fortunately they had a laptop set up with the projector and I didn't need to worry about taking a HDMI lead and hoping it was a recent projector. Unexpectedly I needed to edit an existing OpenOffice presentation to remove a couple of slides and then convert to PDF to send to another company. I had to ask a colleague to do it for me. There are apps that can view OpenOffice files, but no native OpenOffice suite for android. I'd probably make sure I had access to a VNC server in the future and use a VNC client for anything like this. Fail.
Privacy. My thinkpad has full-disk encryption but I didn't bother for Android as I wasn't going to be storing anything sensitive on the machine. My thinkpad has a 3M privacy filter, which is great for airplanes and airports to stop people either side and behind you looking at your screen. The same filters do exist for Android, but are not as straightforward (it of couse only works in one orientation and attaches like a screen protector, so isn't the easiest thing to continuously take on and off, and forces you to use your screen in portrait mode for everything). Fail.
Printing a boarding card. When it was time to return home I was able to use Firefox to check in online, and printing my boarding passes gave me a PDF file. I didn't have any printer apps set up, but it was easy enough to email a PDF to a colleague to print for me. Partial Win.

So in summary I think I got away with it; having just the tablet didn't stop me doing anything that had to be done on the trip and I'll definately do the same thing again in the future for very short trips. For anything more than a couple of days or where connectivity might be an issue I'd miss having a full-featured OS.

Red Hat Security Blog

Thu, 20 Sep 2012 12:54:00 GMT

We now have an official Red Hat Security Blog, and you'll find all my future reports and discussions about security metrics there. In the meantime here are a few already published articles:

Red Hat and CVRF compatibility

Fri, 18 May 2012 12:41:00 GMT

The Common Vulnerability Reporting Framework (CVRF) is a way to share information about security updates in an XML machine-readable format. CVRF 1.1 got released this week and over at Red Hat we've started publishing our security advisories in CVRF format.

Find out more from our FAQ and formatting guide.

Enterprise Linux 5.7 to 5.8 risk report

Tue, 21 Feb 2012 14:52:00 GMT

Red Hat Enterprise Linux 5.8 was released today (February 2012), seven months since the release of 5.7 in July 2011. So let's use this opportunity to take a quick look back over the vulnerabilities and security updates made in that time, specifically for Red Hat Enterprise Linux 5 Server.

Red Hat Enterprise Linux 5 is coming up to its fifth year since release, and is supported for another five years, until 2017.

Errata count

The chart below illustrates the total number of security updates issued for Red Hat Enterprise Linux 5 Server if you had installed 5.7, up to and including the 5.8 release, broken down by severity. It's split into two columns, one for the packages you'd get if you did a default install, and the other if you installed every single package (which is unlikely as it would involve quite a bit of manual effort to select every one). For a given installation, the number of package updates and vulnerabilities that affected you will depend on exactly what packages you have installed or removed.

So, for a default install, from release of 5.7 up to and including 5.8, we shipped 42 advisories to address 118 vulnerabilities. 4 advisories were rated critical, 13 were important, and the remaining 25 were moderate and low.

Or, for all packages, from release of 5.7 up to and including 5.8, we shipped 71 advisories to address 177 vulnerabilities. 7 advisories were rated critical, 16 were important, and the remaining 48 were moderate and low.

Critical vulnerabilities

The 7 critical advisories addressed 20 critical vulnerabilities across 4 different packages:

An update to OpenJDK 6 Java Runtime Environment, (October 2011) where a web site hosting a malicious Java applet could potentially run arbitrary code as the user.

An update to the MIT krb5 telnet daemon (December 2011) where a remote attacker who can access the telnet port of a target machine could use this flaw to execute arbitrary code as root. Note that the krb5 telnet daemon is not installed or enabled by default, and the default firewall rules block remote access to the telnet port. This flaw did not affect the more commonly used telnet daemon distributed in the telnet-server package.

Updates to PHP and PHP 5.3 (February 2012) where a remote attacker could send a specially-crafted HTTP request to cause the PHP interpreter to crash or, possibly, execute arbitrary code. This flaw was caused by the fix for CVE-2011-4885.

Three updates to Firefox (August 2011, September 2011, November 2011) where a malicious web site could potentially run arbitrary code as the user running Firefox.

Updates to correct 19 out of the 20 critical vulnerabilities were available via Red Hat Network either the same day or the next calendar day after the issues were public. The update to krb5 took 2 calendar days because it was public on Christmas day.

Overall, for Red Hat Enterprise Linux 5 since release until 5.8, 98% of critical vulnerabilities have had an update available to address them available from the Red Hat Network either the same day or the next calendar day after the issue was public.

Other significant vulnerabilities

Although not in the definition of critical severity, also of interest during this period were a couple of remote denial of service flaws that were easily exploitable:

A flaw in BIND, CVE-2011-4313, fixed by RHSA-2011:1458 (bind) and RHSA-2011:1459 (bind97). A remote attacker could use this flaw to cause BIND to crash.

A flaw in Apache HTTP Server, CVE-2011-3192, fixed by RHSA-2011:1245. A remote attacker could use this flaw to cause httpd to use an excessive amount of memory and CPU time.

In addition, updates to Firefox, NSS, and Thunderbird were made to blacklist a compromised Certificate Authority.

Previous update releases

To compare these statistics with previous update releases we need to take into account that the time between each update release is different. So looking at a default installation and calculating the number of advisories per month gives the following chart:

This data is interesting to get a feel for the risk of running Enterprise Linux 5 Server, but isn't really useful for comparisons with other major versions, distributions, or operating systems -- for example, a default install of Red Hat Enterprise Linux 4AS did not include Firefox, but 5 Server does. You can use our public security measurement data and tools, and run your own custom metrics for any given Red Hat product, package set, timescales, and severity range of interest.

See also: 5.7, 5.6, 5.5, 5.4, 5.3, 5.2, and 5.1 risk reports.

Making of the SONIK Gravitation music video

Sat, 31 Dec 2011 18:02:00 GMT

The inspiration for the Sonik video for Gravitation came from a local friend of ours, a talented and world-renowned photographer, Adrian Brannan. Ade is famous for his analogue photo collages (please give him a 'like' on his Facebook page):

We often wondered how the same effect would look if rendered with video. With video you've got the extra element of time, each segment of the mosaic can be running from a different starting point, with a different speed, and even a different direction. In addition the segments themselves can move over time. Would this end up with an effect that was just too much of a mess? Or would it give an effect that helps visualise the consequence of spacetime?

We started by taking several videos at three different locations over the period of a year with a Kodak Zi8 camera. A motorway bridge over the M74, just outside the Buchanan shopping center in Glasgow, and a bench in Strathclyde park. Lining up the images was done roughly by using lines drawn on acetate stuck over the camera screen.

The software to do the mosaic effect was hand-written. We used a simple scripting language, Perl, and the image library GD. On a relatively modern Linux PC running Fedora 16 we can render near real-time 720p HD even when handling 300 segments of mosaic. A simple language controls which parts of the screen come from which video, and the first half of the music video uses this with simple effects having just a few boxes overlayed:

Later in the video things get more complicated, using randomisation to pick the location and movement of each segment:

We used our scripts to create a number of ~13 second segments, then put them all together using kdenlive. The intro and outro were taken from a different video from a hotel room in London Victoria; the intro using a 'miniature' effect, and outro using the randomised segments applied to a single video.

The Perl script and a 5 frame example is available to download: 2011-sonik-vid-example.tar.bz2 (1.4M)

Watch the full video, or click through to YouTube to see it in HD:

Enterprise Linux 6.1 to 6.2 risk report

Thu, 08 Dec 2011 16:42:00 GMT

Red Hat Enterprise Linux 6.2 was released this week (Dec 2011), just over six months since the release of 6.1 in May 2011. So let's use this opportunity to take a quick look back over the vulnerabilities and security updates made in that time, specifically for Red Hat Enterprise Linux 6 Server.

Errata count

The chart below illustrates the total number of security updates issued for Red Hat Enterprise Linux 6 Server if you had installed 6.1, up to and including the 6.2 release, broken down by severity. It's split into two columns, one for the packages you'd get if you did a default install, and the other if you installed every single package (which is unlikely as it would involve a bit of manual effort to select every one). For a given installation, the number of package updates and vulnerabilities that affected you will depend on exactly what you have installed or removed.

So, for a default install, from release of 6.1 up to and including 6.2, we shipped 36 advisories to address 121 vulnerabilities. 2 advisories were rated critical, 10 were important, and the remaining 24 were moderate and low.

Or, for all packages, from release of 6.1 up to and including 6.2, we shipped 88 advisories to address 218 vulnerabilities. 10 advisories were rated critical, 16 were important, and the remaining 62 were moderate and low.

Critical vulnerabilities

The 10 critical advisories addressed 31 critical vulnerabilities across 3 components:

Two updates to the OpenJDK 6 Java Runtime (June 2011, October 2011) where a malicious web site presenting a Java applet could potentially run arbitrary code as the user running a web browser.

Four updates to Firefox (June 2011, August 2011, September 2011, November 2011) where a malicious web site could potentially run arbitrary code as the user running Firefox.

Four updates to Thunderbird (June 2011, August 2011, September 2011 November 2011) where a malicious email message could potentially run arbitrary code as the user running Thunderbird.

Updates to correct all of the 31 critical vulnerabilities were available via Red Hat Network either the same day or the next calendar day after the issues were public.

Other significant vulnerabilities

Although not in the definition of critical severity, also of interest during this period were a few flaws that were high risk or easily exploitable:

A flaw in Bind, CVE-2011-4313 fixed by RHSA-2011:1458 where a malicious client could cause Bind to stop responding, a denial of service attack. This flaw was discovered by it being accidentally triggered in the wild.
A flaw in the Apache HTTP Server, CVE-2011-3192, fixed by RHSA-2011:1245, where a remote attacker could cause a denial of service attack. This was discovered due to a public exploit.
A flaw in RPM, CVE-2011-3378 fixed by RHSA-2011:1349 where a specially-crafted RPM package that, when queried or installed, would cause rpm to crash or, potentially, execute arbitrary code prior to any signature checking. We're not aware of any working exploits for this issue.
Updates to blacklist the DigiNotar Certificate Authority.

Previous update releases

This data is interesting to get a feel for the risk of running Enterprise Linux 6 Server, but isn't really useful for comparisons with other major versions, distributions, or operating systems -- for example, a default install of either Red Hat Enterprise Linux 4AS and 6 Server does not include Firefox, but a default install of 5 Server does. You can use our public security measurement data and tools, and run your own custom metrics for any given Red Hat product, package set, timescales, and severity range of interest.

Vulnerability Acknowledgements for Red Hat online services

Fri, 18 Nov 2011 12:03:00 GMT

When we get notified of a security issue affecting a Red Hat product in advance we give an acknowledgement in the security advisory and in our CVE database.

We've now created a page to give acknowledgements to the companies and individuals that report issues in our online services, such as finding a cross-site scripting flaw in a Red Hat web site, or a vulnerability in OpenShift.