While the firewall isn’t designed to block exploit attempts for this vulnerability, its general protection will stop some of the attempts, since the attacker is passing invalid data as part of request. (That is one of the reasons that the many WordPress security plugins that try to hide usage of WordPress are not really providing security.) As an example of that, here are some of the attempts that were blocked by our new firewall on this website so far:
Wordpress log4j software#
That they are not impacted doesn’t mean that hackers won’t try to exploit the vulnerability on WordPress websites, since hacker will try to exploit vulnerabilities without knowing what software underlies a website. WordPress and WordPress plugins are written in PHP, so a vulnerable Java library won’t impact them. From monitoring we do to keep track of discussion of vulnerabilities in WordPress plugins for our service, we have noticed that there are questions among some about the impact this has on WordPress website and WordPress plugins. It is clearly there if you look for it, but you do not expect it to be there, because logging statements are not supposed to change the system state.Over the last few days, there has been quite a bit of news coverage of a vulnerability in a Java library named Log4j. The debug statement was changing the state of the system. After taking a closer look, I found I had deleted this: DEBUG("Counter value is: " + counter++)
Wordpress log4j code#
I really do not expect it to ‘lookup’ something, anything, over the network.Ī very long time ago, I was cleaning up some very verbose debugging statements in code that I did not write, and my changes broke the application. I expect my logger to write to a log file. JDK 17 is awesome!Īnd as a longer term lesson – keep things simple! Libraries should do what you expect them to do.
Wordpress log4j upgrade#
And upgrade your JDK to something reasonably up-to-date. Keep all your other dependencies up to date as well, while you’re at it. But most importantly – upgrade your log4J dependencies to the most recent versions as soon as possible. Plenty of others have reviewed the possible mitigations for Log4Shell better than I could. An RCE vulnerability is one of the most dangerous kinds of exploits.
Wordpress log4j install#
Once some foreign code is running on my server, it can connect to a remote server, download anything it wants, install rootkits, upload my data to the internet and take a nice long stroll through my network. This is an RCE – a Remote Code Execution vulnerability. What IS important is that it is entirely possible that the remote server can reply to my hapless logger with a java class file – and Log4J would load that class and run it! That basically means that a correctly crafted input to a text box on my site, which is logged by my server via Log4J, will cause my server to download some unknown code from the internet and run it, no questions asked.
It is slightly complicated, not really interesting and generally useless for the absolute vast majority of developers. I am not going to get into the details of JNDI and LDAP. What if the log is not 10.10.10.10? What if it’s ‘ ‘? And that machine is running an actual LDAP server? This is an incredibly simple Denial-of-Service attack. If the user sends a few of these requests, my server will exhaust whatever thread pool it is using and stop serving traffic. Or another example that is almost as simple, with a basic parameter: LOG.info("This is a ” and I logged it with Log4J, my code is stuck. Here is a simple example: LOG.info("This is a valid log message") What goes into a log message? It depends. It is the most basic form of Observability you can add to a project, giving you some insight into what is going on in your code as it is running. Logging is one of the first things you add to any project. Log4J is one of the most commonly used logging frameworks in the JVM world. I will walk you through some simple usage of the Log4J library and then show how user input that reaches this library can cause truly unexpected, and potentially disastrous, outcomes. In this post I will show a really basic example of how this vulnerability actually works. You have probably heard of Log4Shell, the security vulnerability that has ‘earned’ itself an NIST rank of 10: Source:
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