Mark J Cox

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

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 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.

When do we push most advisories?

Fri, 11 Nov 2011 15:25:00 GMT

We pushed an update to Flash Player for Red Hat Enterprise Linux Supplementary today, on a Friday, because it fixed Critical vulnerabilities. But we try not to push updates on a Friday unless they are critical and already public.

So let's take a look at the most common times and days we push advisories for Red Hat Enterprise Linux 4, 5, and 6 (including Supplementary) using a heatmap:

The more advisories pushed for a given date and hour, the darker that section of the graph is. So the most popular times for pushing advisories are Tuesdays at 10am and 2pm Eastern US time, Fridays are pretty light for pushes, and there was nothing during the weekends. The spread of the graph shows that we push advisories when they are ready, rather than waiting to a fixed day and time, in order to reduce the risk to users.

All the data used to create this graph is available as part of our public metrics. Thanks to Sami Kerola for the R code from which I based my graph generation.

Peggy2 Text Scroller

Mon, 29 Aug 2011 23:00:00 GMT

For my Birthday my wife bought me a Peggy 2 kit, and I finally got around to adding the 625 10mm green LEDs. Some of the example programs are pretty neat but I wanted to make a side scroller with a nice font ready for halloween.

I decided on the Liberation Sans Narrow font, drew up a string of characters in The Gimp, converted it to have only 4 levels, then used a quick perl script to convert the image into program data for the scroller. I'm pretty happy with how it turned out. The scroller, image, and script are available here.

Six years of Red Hat Enterprise Linux 4

Wed, 17 Aug 2011 09:58:00 GMT

Every year since Red Hat Enterprise Linux 4 was released we've published a risk report where we look at the state of security of the distribution. We investigate the key vulnerabilities, metrics on vulnerability counts, and how users could have been exploited by them. The Six Years of Red Hat Enterprise Linux 4 report (PDF) covering Feb 2005-2011 was published today.

"Red Hat knew about 51.5% of the security vulnerabilities that we fixed in advance. The average time between Red Hat knowing about an issue and it being made public was 23 days (median 10 days).... A default installation of Red Hat Enterprise Linux 4 AS was vulnerable to 20 critical security issues over the first six years. "

The data we publish is interesting to get a feel for the risk of running Enterprise Linux, but isn't really useful for comparisons with other distributions, or operating systems. One important difference is that it is Red Hat policy to count vulnerabilities and allocate CVE names to all issues that we fix, including ones that are found internally. This is not true for many other vendors including folks like Microsoft and Adobe who do not count or disclose issues they fix which were found internally.

Red Hat's Most Serious Flaw Types for 2010

Tue, 09 Aug 2011 11:22:00 GMT

A few weeks ago the 2011 update to the CWE/SANS Top 25 Most Dangerous Software Errors was published. As part of our contribution to this update we analysed the most severe vulnerabilities that affected Red Hat since the last update and mapped each one to the appropriate Common Weakness Enumeration (CWE) type.

The table below lists all vulnerabilities which have a CVSS score of 7 or more ('high'), that we fixed in any product during calendar year 2010.

Most common CWE were:

Buffer Copy without Checking Size of Input (CWE-120): 8 vulnerabilities.
Race Condition (CWE-362): 5 vulnerabilities.

CVE	CWE	2011 top 25?	CVSS base score	Fixed in
CVE-2007-4567	CWE-476	no	7.8	Red Hat Enterprise Linux 5 (kernel)
CVE-2009-0778	CWE-770	no	7.1	Red Hat Enterprise Linux 5 (kernel)
CVE-2009-1385	CWE-191	no	7.1	Red Hat Enterprise Linux 5 (kernel)
CVE-2009-3080	CWE-129	no	7.2	Red Hat Enterprise Linux 3, 4, 5, MRG (kernel)
CVE-2009-3245	CWE-252	no	7.6	Red Hat Enterprise Linux 3, 4, 5 (openssl)
CVE-2009-3726	CWE-476	no	7.2	Red Hat Enterprise Linux 4, 5, MRG (kernel)
CVE-2009-4005	CWE-127	no	7.1	Red Hat Enterprise Linux 4 (kernel)
CVE-2009-4027	CWE-362	no	7.8	Red Hat Enterprise Linux 5 (kernel)
CVE-2009-4141	CWE-416	no	7.2	Red Hat Enterprise Linux 5, MRG (kernel)
CVE-2009-4212	CWE-191	no	10.0	Red Hat Enterprise Linux 3, 4, 5 (krb5)
CVE-2009-4272	CWE-764	no	7.8	Red Hat Enterprise Linux 5 (kernel)
CVE-2009-4273	CWE-78	yes	7.9	Red Hat Enterprise Linux 5 (systemtap)
CVE-2009-4537	CWE-120	yes	7.1	Red Hat Enterprise Linux 4, 5, MRG (kernel)
CVE-2009-4895	CWE-362	no	7.2	Red Hat Enterprise MRG (kernel)
CVE-2010-0008	CWE-606	no	7.8	Red Hat Enterprise Linux 4, 5 (kernel)
CVE-2010-0291	CWE-822	no	7.2	Red Hat Enterprise Linux 5 (kernel)
CVE-2010-0738	CWE-424	no	7.5	JBoss Enterprise Application Platform 4.2, 4.3
CVE-2010-0741	CWE-20	no	7.1	Red Hat Enterprise Linux 5 (kvm)
CVE-2010-1084	CWE-120	yes	7.2	Red Hat Enterprise Linux 5 (kernel)
CVE-2010-1086	CWE-20	no	7.8	Red Hat Enterprise Linux 4, 5 (kernel)
CVE-2010-1087	CWE-362	no	7.2	Red Hat Enterprise Linux 5 (kernel)
CVE-2010-1166	CWE-823	no	7.6	Red Hat Enterprise Linux 5 (xorg-x11-server)
CVE-2010-1173	CWE-120 *	yes	7.1	Red Hat Enterprise Linux 4, 5 (kernel)
CVE-2010-1188	CWE-416	no	7.8	Red Hat Enterprise Linux 3, 4, 5 (kernel)
CVE-2010-1436	CWE-120	yes	7.2	Red Hat Enterprise Linux 5 (kernel)
CVE-2010-1437	CWE-362	no	7.2	Red Hat Enterprise Linux 4, 5 (kernel)
CVE-2010-2063	CWE-823	no	7.5	Red Hat Enterprise Linux 3, 4, 5 (samba)
CVE-2010-2235	CWE-77	no	7.1	Red Hat Network Satellite Server 5.3 (cobbler)
CVE-2010-2240	CWE-788	no	7.2	Red Hat Enterprise Linux 3, 4, 5, MRG (kernel)
CVE-2010-2248	CWE-682	no	7.1	Red Hat Enterprise Linux 4, 5 (kernel)
CVE-2010-2492	CWE-805	no	7.2	Red Hat Enterprise Linux 5, 6 (kernel)
CVE-2010-2521	CWE-805	no	8.3	Red Hat Enterprise Linux 4, 5, MRG (kernel)
CVE-2010-2798	CWE-476	no	7.2	Red Hat Enterprise Linux 5 (kernel)
CVE-2010-2962	CWE-823	no	7.2	Red Hat Enterprise Linux 6, MRG (kernel)
CVE-2010-3069	CWE-129	no	8.3	Red Hat Enterprise Linux 3, 4, 5, 6 (samba)
CVE-2010-3081	CWE-131	yes	7.2	Red Hat Enterprise Linux 3, 4, 5, 6, MRG (kernel)
CVE-2010-3084	CWE-120	yes	7.2	Red Hat Enterprise Linux 6 (kernel)
CVE-2010-3301	CWE-129	no	7.2	Red Hat Enterprise Linux 6 (kernel)
CVE-2010-3302	CWE-120	yes	7.1	Red Hat Enterprise Linux 6 (openswan)
CVE-2010-3308	CWE-120	yes	7.1	Red Hat Enterprise Linux 6 (openswan)
CVE-2010-3432	CWE-805 *	no	7.8	Red Hat Enterprise Linux 4, 5, 6, MRG (kernel)
CVE-2010-3705	CWE-788	no	8.3	Red Hat Enterprise Linux 6, MRG (kernel)
CVE-2010-3708	CWE-77	no	7.5	JBoss Enterprise Application Platform 4.3, SOA Platform 4.2
CVE-2010-3752	CWE-78	yes	7.1	Red Hat Enterprise Linux 6 (openswan)
CVE-2010-3753	CWE-78	yes	7.1	Red Hat Enterprise Linux 6 (openswan)
CVE-2010-3847	CWE-426	no	7.2	Red Hat Enterprise Linux 5, 6 (glibc)
CVE-2010-3856	CWE-426	no	7.2	Red Hat Enterprise Linux 5, 6 (glibc)
CVE-2010-3864	CWE-362	no	7.6	Red Hat Enterprise Linux 6 (openssl)
CVE-2010-3904	CWE-822	no	7.2	Red Hat Enterprise Linux 5, 6 (kernel)
CVE-2010-4170	CWE-88	no	7.2	Red Hat Enterprise Linux 4, 5, 6 (systemtap)
CVE-2010-4179	CWE-862	yes	7.5	Red Hat Enterprise MRG (cumin)
CVE-2010-4344	CWE-120	yes	7.5	Red Hat Enterprise Linux 4, 5 (exim)

* - in both these cases the outcome is not a buffer overflow as the possible overflow is detected and instead converted into an abort (DoS)

Enterprise Linux 5.6 to 5.7 risk report

Wed, 27 Jul 2011 12:32:00 GMT

Red Hat Enterprise Linux 5.7 was released last week (July 2011), six months since the release of 5.6 in January 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.

Errata count

The chart below illustrates the total number of security updates issued for Red Hat Enterprise Linux 5 Server if you had installed 5.6, up to and including the 5.7 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 5.6 up to and including 5.7, we shipped 27 advisories to address 109 vulnerabilities. 3 advisories were rated critical, 12 were important, and the remaining 12 were moderate and low.

Or, for all packages, from release of 5.6 to and including 5.7, we shipped 58 advisories to address 172 vulnerabilities. 4 advisories were rated critical, 20 were important, and the remaining 34 were moderate and low.

Critical vulnerabilities

The 4 critical advisories addressed 34 critical vulnerabilities across just 2 different packages:

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

Three updates to Firefox (March 2011, April 2011, June 2011) where a malicious web site could potentially run arbitrary code as the user running Firefox.

Updates to correct all of the 34 critical vulnerabilities were available via Red Hat Network either the same day or the next calendar day after the issues were public.

Overall, for Red Hat Enterprise Linux 5 since release until 5.7, 97% 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 flaws that were easily exploitable:

A flaw in dhcp, CVE-2011-0997, fixed by RHSA-2011:0428, where a malicious DHCP server could send a response that could lead to arbitrary code execution on connecting clients.

A flaw in glibc, CVE-2011-0536, fixed by RHSA-2011:0412, where a local user could gain root privileges.

In addition, updates to Firefox and NSS were made to blacklist a number of compromised SSL certificates.

Previous update releases

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: 5.5 to 5.6, 5.4 to 5.5, 5.3 to 5.4, 5.2 to 5.3, 5.1 to 5.2, and 5.0 to 5.1 risk reports.

Hiring three Security Response Team members

Tue, 07 Jun 2011 11:57:00 GMT

Red Hat has an unrivaled security record when it comes to addressing security flaws in our products. We reduce the risk to customers using our products by constantly monitoring for vulnerabilities and threats, triaging their impact to our customers, and addressing those that matter the most quickly. The Red Hat Security Response Team are responsible for dealing with security vulnerabilities in Red Hat products and services and has a team spanning nine countries.

We've currently got three positions in the team currently open. One is focused on Java (JBoss) technologies, another on our new Cloud services, and a final one on our Enterprise Linux product.

Would you like to be part of our dynamic team, and help protect Red Hat's customers and the open source community as a whole from security vulnerabilities?

Each of the positions are challenging and demanding; every day you'll be investigating different issues affecting different products and codebases, having to manage your time on the issues with the greatest impact.

Some of the tasks of the job include (but are not limited to):

Rapidly responding to new security issues. You'll need to be able to think fast, analyze complex problems, use your judgement to assess vulnerability severities and risks, and switch your priorities to ensure that serious issues get immediate attention.
Investigating how security flaws specifically impact your products. Research how the flaws can be exploited by attackers; by code analysis, testing exploits, or writing proof of concept tests.
Communicating about flaws with our software developers, managers, quality engineers, upstream project developers, as well as our peers in the security response teams of other vendors.
Developing advice and technical documentation for security advisories.
Responsibility for tracking vulnerabilities through the entire update release lifecycle and ensuring that customers get the right fixes with the right advice at the right time.

We can be flexible with working location. So if this interests you, email me a CV/resume (to mjc at redhat.com) as not all the jobs are on our careers page yet.

Enterprise Linux 6.0 to 6.1 risk report

Fri, 20 May 2011 08:30:00 GMT

Red Hat Enterprise Linux 6.1 was released this week (May 2011), just over six months since the release of 6.0 in October 2010. 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 6.0, up to and including the 6.1 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 6.0 up to and including 6.1, we shipped 54 advisories to address 195 vulnerabilities. 2 advisories were rated critical, 29 were important, and the remaining 23 were moderate and low.

Or, for all packages, from release of 6.0 up to and including 6.1, we shipped 102 advisories to address 345 vulnerabilities. 8 advisories were rated critical, 39 were important, and the remaining 55 were moderate and low.

These figures include 10 advisories we released on the day we shipped 6.0. This was because we froze package updates some months before releasing the product. Two of those updates were rated critical, an update to Firefox, and to Samba.

Critical vulnerabilities

The 8 critical advisories addressed 37 critical vulnerabilities across 4 components:

An update to Samba (October 2010) where a malicious client could potentially run arbitrary code as the Samba server. Samba is a default install package but the server is not enabled by default.

Four updates to Firefox (October 2010, December 2010, March 2011, April 2011) where a malicious web site could potentially run arbitrary code as the user running Firefox.

Two updates to Thunderbird (March 2011, April 2011) where a malicious email message could potentially run arbitrary code as the user running Thunderbird.

An update to Pango (March 2011) where an application using Pango to parse untrusted font data (such as Firefox) could potentially run arbitrary code as the privileges of the user. Pango is a default install package.

Updates to correct all of the 37 critical vulnerabilities were available via Red Hat Network either the same day or the next calendar day after the issues were public.

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 Red Hat Enterprise Linux 4AS and 6 Server 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.