Sven Welzel — Der Blog

Category: code

Cape Town #loadshedding lookup tool updated

Load shedding Cape Town lookup tool updated

The loadshedding lookup tool for Cape Town has been updated! You can now select your suburb by name, and the schedule will switch to the new, updated 16-day rotational schedule automatically on 1 Feb 2015. The tools tells you when you will be load shed by day of the week (on the old schedule) and day of the month (on the new schedule) based on the area, and stage (stage 1, 2, 3a and 3b) of load shedding. This tool is *only* applicable to areas supplied by the Cape Town municipality, i.e. if you buy electricity from the City of Cape Town, or receive an invoice from said municipality.

If you are an Eskom direct consumer, you’ll have to visit the Eskom load shedding schedule. (more…)

January 24, 2015
Load shedding lookup tool for new #loadshedding schedule – Cape Town, 2015

A lookup tool for the new loadshedding schedule for Cape Town from Feb 2015 is now available at https://blog.sven.co.za/shed. Day is autoselected, choose your area and choose the stage. Beyond that, you are then given the times that load shedding is set to take place on that day.

Both the old and new schedules are now accessible, and lookups are based on the new schedule from midnight, 1 Feb 2015.

January 20, 2015
Your mobile number is being sent to web pages

Depending on the mobile network provider you use (MTN doesn’t seem to be affected in ZA at the moment, Vodacom in ZA leaks this information), and device used, your IMEI and MSISDN (mobile number) are being sent to each web server you access via the mobile data network. In addition, tracker headers are being added.

You can see this here: https://blog.sven.co.za/sniff/ (access the page from your mobile phone on 3G/4G/GPRS or EDGE). (more…)

October 29, 2014
`Shellshock` Bash Patch update – pipe directly to sh to secure your machine

Recently, I made the script to patch your BASH environment available on this site, but that meant a need to copy and paste.

Using a user with the appropriate rights, you can now pipe directly using a quiet wget to make the full recompile to most recent BASH version possible.

All you need is this line: (more…)

October 8, 2014
`Shellshock` bash vulnerability fix and update in case of slow or unavailable repositories

Updated to latest kernel patch bash43-30

You’ve heard of ShellShock, and the bash-exploits that are currently doing the rounds, across platforms, that make use of these bugs (CVE-2014-6271 and the volumes of additional updates including CVE-2014-6277, CVE-2014-7186, CVE-2014-7187 and CVE-2014-7169, but to name a few). Proofs of Concept are being collected here… The below works as a vulnerability fix for older Ubuntu LTS and non-LTS versions, Debian (eg Squeeze) as well as Fedora and RedHat/CentOS, and applies all up-to-date patches to Bash.

bash – as a shell – is a tried and trusted component. Some legacy systems’ repositories – be they apt, yum or other – may no longer be kept up to date. Alternatively, they may not be being kept up-to-date enough for your liking. And you want to close the bash issue in the best way you know how.

Easy workaround is a recompile of the bash shell yourself:

(more…)

September 29, 2014
How to block or drop attacker with null route
Quick note to myself, as I keep forgetting the syntax, though it is so easy — to block an incoming connection by null routing or rejecting the connection is as simple as
```
route add -host IP reject
```
To apply this to a whole subnet range, use the -net as you would with the /24 mask (or the appropriate subnet, /29 or smaller should do), eg
```
route add -net IP/RANGE reject
```
To undo this,
```
route delete IP
```
January 14, 2013
Rsync – copy file differences to third directory

So you have a snapshot of data on one drive, and the current state of data on the second drive. How do you copy the difference between the two drives into a third directory?

Rync comes to the rescue here. And it doesn’t take much:

(more…)

April 6, 2012
960 and a variety of other styling options

From the provider of formalize.me (consistent styling for forms), Nathan Smith’s presentation from April 2011 about the 960 grid system (960.gs) framework, the rationale and alternatives

Refresh OKC

View more presentations from Nathan Smith

May 24, 2011
Three Oh Five – WordPress Upgrade are out

The upgrade to 3.0.5 was resleased yesterday. From the release notes:

Two moderate security issues were fixed that could have allowed a Contributor- or Author-level user to gain further access to the site.

One information disclosure issue was addressed that could have allowed an Author-level user to view contents of posts they should not be able to see, such as draft or private posts.

Two security enhancements were added. One improved the security of any plugins which were not properly leveraging our security API. The other offers additional defense in depth against a vulnerability that was fixed in previous release.

Download and upgrade now!

February 8, 2011
Expire private images to protect privacy on the Internet?

A new product over at x-pire.net (which redirects to x-pire.de) was unveiled in Germany today, with the aim of embedding expiry times and information into images so that they cannot be viewed after a certain time. In that way there should be a maximum lifespan to digital images on the web to prevent future embarassment, usage etc. At this stage, the prototype is available as plug-in for Firefox (as well as some other browsers in future), and expounds the idea of a ‘forgetful internet’ so that information is not immortal on the web. (more…)

January 11, 2011
Upgrade to WordPress 3.0.4 – HTML Sanitation bug

From the WordPress Development Blog:

Version 3.0.4 of WordPress, available immediately through the update page in your dashboard or for download here, is a very important update to apply to your sites as soon as possible because it fixes a core security bug in our HTML sanitation library, called KSES. I would rate this release as “critical.” (more…)

December 30, 2010
Nudge, nudge, wink, wink – WordPress Upgrade

… it’s time to go 0-3, I think — WordPress 3.0.3 is out – but the update is really only applicable to remote publishing-enabled systems…

WordPress 3.0.3 is available and is a security update for all previous WordPress versions.

This release fixes issues in the remote publishing interface, which under certain circumstances allowed Author- and Contributor-level users to improperly edit, publish, or delete posts.

December 9, 2010
WordPress 3.0.2 is out

Don’t forget to upgrade inplace or download! It is a mandatory security update for all previous WordPress versions, and upgrades are easy 🙂

December 2, 2010
Stuxnet lessons – and resources

Just a quick grouping of resources relating to Stuxnet resources and analysis after the targeted infections of the frequency converters of the Vaasa, Finland based Vacon (though Vacon publicly denies this) and Iranian company Fararo Paya.

The bottomline takeaway – never use default passwords (partical attack vector of the PLCs and SCADAs), and keep systems patched (4 zero-day Windows-based attacks). And don’t allow USB devices on a production network (the entry point of the 0.5Mb virus written in C and C++)… (more…)

November 27, 2010
Proxying all Linux Traffic – set web access for Ubuntu behind a proxy

So that it’s documented… I’m using port 8080 as the default port as the likelyhood of your upstream proxy being on 8080 is high – else, typical proxy ports are, of course, 80, 800 (transpartent), 8000, 3128 (squid)

To force your server to force web traffic via a proxy, just two quick things to set – in /etc/environment, export one (or two) variables: (more…)

October 22, 2010
Search and view gzip’d files

You knew it already – but I keep forgetting – the power of zgrep and zcat both of which behave as their z-less counterparts.

So, to search a gzip’d file, you can simply zgrep <term> <filename.gz>, or to cat/view it, zcat <filename.gz>

Good to come back to in case of impending forgetfulness…

October 21, 2010
Intel Gigabit Ethernet Card on an old kernel?

For self-reference, mainly:

For the Intel Corporation 82574L Gigabit Network Connection on an old kernel that doesn’t have the drivers compiled into it – get the driver and

make install

it on the platform you’re on, and to be sure (if it doesn’t get done for you) to copy to /lib/modules/2.4.36/kernel/drivers/net/ (your kernel may vary, this is an example only) (more…)

October 21, 2010
Firefox: Paste HTML code from one child frame to parent text-box – src stripped

Here’s something fun: use Firefox 3.6.9 to have a set of Javascript code in a child frame append HTML code to a text box in the parent frame, and content of the string is modified:

what was

<img src="foo.jpg" alt="bar" width="1" height="1" />

becomes

<img alt="bar" width="1" height="1" />

which is pretty pointless… (more…)

September 10, 2010
Search all files for TEXT in bash

To find all files by file name containing THE TEXT I SEEK:

grep -lir "THE TEXT I SEEK" *

(more…)

August 9, 2010
WordPress 3.0.1 – I’m sure you’ve upgraded already

I’m sure you’ve done it already, but WordPress 3.0.1 (a maintenance release) is out since Friday and you should have upgraded (and updated the database) already by downloading the 3.0.1 version.

List of revised files:

(more…)

August 9, 2010