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Displaying posts with tag: Security (reset)
How to test if CVE-2015-0204 FREAK SSL security flaw affects you

The CVE-2015-0204 FREAK SSL vulnerability abuses intentionally weak “EXPORT” ciphers which could be used to perform a transparent Man In The Middle attack. (We seem to be continually bombarded with not only SSL vulnerabilities but the need to name vulnerabilities with increasing odd names.)

Is your server vulnerable?

This can be tested using the following GIST

If the result is 0; the server is not providing the EXPORT cipher; and as such is not vulnerable.

Is your client vulnerable?

Point your client to https://oneiroi.co.uk:4443/test if this returns “Vulnerable” then the client is vulnerable, if you find a connection error your client should not be vulnerable for example:

root@host:/tmp$ openssl …

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Introducing ‘MySQL 101,’ a 2-day intensive educational track at Percona Live this April 15-16

Talking with Percona Live attendees last year I heard a couple of common themes. First, people told me that there is a lot of great advanced content at Percona Live but there is not much for people just starting to learn the ropes with MySQL. Second, they would like us to find a way to make such basic content less expensive.

I’m pleased to say we’re able to accommodate both of these wishes this year at Percona Live! We have created a two-day intensive track called “MySQL 101” that runs April 15-16. MySQL 101 is designed for developers, system administrators and DBAs familiar with other databases but not with MySQL. And of course it’s ideal for anyone else who would like to expand their professional experience to include MySQL. The sessions are designed to lay a solid foundation on many aspects of MySQL development, design and …

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MySQL Backup Strategy – Slides

Hi there, it’s been a few months since Percona Live London has finished, but I managed just now to get sometime to post the slides from my presentation about backups. Please, take a look and feel free to comment.

Pdf Version


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GHOST vulnerability (CVE-2015-0235) Percona response

Cloud security company Qualys announced Tuesday the issues prevalent in glibc since version 2.2 introduced in 2000-11-10 (the complete Qualys announcement may be viewed here). The vulnerability, CVE-2015-0235, has been dubbed “GHOST.”

As the announcement from Qualys indicates, it is believed that MySQL and by extension Percona Server are not affected by this issue.

Percona is in the process of conducting our own review into the issue related to the Percona Server source code – more information will be released as soon as it is available.

In the interim the current advisory is to update your glibc packages for your distributions if they are in fact vulnerable. The C code from the Qualys announcement may aid in your diagnostics, section 4 of …

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MySQL and the GHOST: glibc gethostbyname buffer overflow

Qualys announced they had found an exploit in one of the Linux core libraries – glibc – using a buffer overflow technique in gethostbyname(). They have developed a proof-of-concept in which simply sending a specially created e-mail to a mail server enabled them to create a remote shell to the Linux machine. According to Qualys, “This bypasses all existing protections (like ASLR, PIE and NX) on both 32-bit and 64-bit systems.”. How does it affect MySQL servers? Read on!

The vulnerable library call provides DNS name resolution and although it’s been obsoleted in favour of other calls, it is still widely used by both legacy and modern applications.

Having a quick search, MySQL does not seem to rely on gethostbyname() almost at all. A few uses can be found in MySQL Cluster code (NDB), …

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How to Use SSL and MySQL Client Library in the Same Binary!

We plan to hide (not export) the symbols of the SSL library used by the MySQL client library. As step one in that effort, we plan to hide all of the non-documented symbols because we want to stop polluting the MySQL client program’s namespace.

Consider a requirement where there the OpenSSL and MySQL client library functions are both used directly to generate a binary. If the order of linking used is 1. MySQL client library (i.e libmysqlclient) and then 2. OpenSSL library (i.e libcrypto), then using the created binary will result in a crash.

The Reason why it will crash is as follows: The libmysqlclient library already has the built-in yaSSL library and has exported its symbols. The yaSSL and OpenSSL libraries share some of the same symbol names, so the executable which is prepared in the above said order, will resolve the OpenSSL symbols indirectly using the libmysqlclient library (yaSSL) rather than using …

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Different SSL setups for MySQL

Using a CRL with MySQL

So assume you just uploaded the certificate you use to identify yourself to the MySQL server to Github or some other place it doesn't belong...and there is no undelete.

First: Don't panic.
Often a password is required besides a certificate to connect to the server. So someone with the certificate can't use it without the password. The certificate itself might be protected by a password, but that's really rare. Also access to MySQL and/or your account should be limited to certain IP's.

The next step is to revoke the certificate. This is possible since MySQL 5.6.3 by using a Certificate Revocation List (CRL).
A CRL is a list of the serials of the revoked certificates and signed by the CA. So this will only work if the certificates have unique serials.

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File carving methods for the MySQL DBA

This is a long overdue blog post from London’s 44con Cyber Security conference back in September. A lot of old memories were brought to the front as it were; the one I’m going to cover in this blog post is: file carving.

So what is file carving? despite the terminology it’s not going to be a full roast dinner; unless you have an appetite for data which as you’re here I’m assuming you have.

The TL;DR of “what is file carving” is taking a target blob of data (often a multi GB / TB file) and reducing it in to targeted pieces of data, this could be for instance grabbing all the jpeg images in a packet capture / mysqldump; or pulling that single table/schema out of a huge mysqldump with –all-databases (if you’re not using mydumper you really …

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(More) Secure local passwords in MySQL 5.6 and up

I log into a lot of different servers running MySQL and one of the first things I do is create a file in my home directory called ‘.my.cnf’ with my credentials to that local mysql instance:

[client]
user=root
password=secret

This means I don’t have to type my password in every time, nor am I tempted to include it on the command line with -p and get the dreaded (but completely accurate):

Warning: Using a password on the command line interface can be insecure.

MySQL 5.6 introduces a utility to make this easier and more secure. First, let’s start with a new mysqld instance with a blank root password and make it more secure:

[vagrant@localhost ~]$ mysqladmin -u root password
New password:secret
Confirm new password:secret
[vagrant@localhost ~]$ mysql -u root
ERROR 1045 (28000): Access denied for user …
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