Pasha Kravtsov

Author Archives: Pasha Kravtsov

Cloudflare is adding Drupal WAF Rule to Mitigate Critical Drupal Exploit

Drupal has recently announced an update to fix a critical remote code execution exploit (SA-CORE-2018-002/CVE-2018-7600). In response we have just pushed out a rule to block requests matching these exploit conditions for our Web Application Firewall (WAF). You can find this rule in the Cloudflare ruleset in your dashboard under the Drupal category with the rule ID of D0003.

Drupal Advisory: https://www.drupal.org/sa-core-2018-002

Cloudflare is adding Drupal WAF Rule to Mitigate Critical Drupal Exploit

Drupal has recently announced an update to fix a critical remote code execution exploit (SA-CORE-2018-002/CVE-2018-7600). This patch is to disallow forms and form fields from starting with the “#” character which results in remote code execution.

We have also in accordance, just pushed out a rule to block requests matching these exploit conditions for our Web Application Firewall (WAF). You can find this rule in the Cloudflare ruleset in your dashboard under the Drupal category with the rule ID of D0003.

Drupal Advisory: https://www.drupal.org/sa-core-2018-002

A Different Kind of POP: The Joomla Unserialize Vulnerability

At CloudFlare, we spend a lot of time talking about the PoPs (Points of Presence) we have around the globe, however, on December 14th, another kind of POP came to the world: a vulnerability being exploited in the wild against Joomla’s Content Management System. This is known as a zero day attack, where it has been zero days since a patch has been released for that bug. A CVE ID has been issued for this particular vulnerability as CVE-2015-8562. Jaime Cochran and I decided to take a closer look.

The Joomla unserialize vulnerability

In this blog post we’ll explain what the vulnerability is, give examples of actual attack payloads we’ve seen, and show how CloudFlare automatically protects Joomla users. If you are using Joomla with CloudFlare today and have our WAF enabled, you are already protected.

The Joomla Web Application Firewall rule set is enabled by default for CloudFlare customers with a Pro or higher plan, which blocks this attack. You can find it in the Joomla section of the CloudFlare Rule Set in the WAF Dashboard.

The WAF rule for protecting against the Joomla Unserialize Vulnerability

What is Joomla?

Joomla is an open source Content Management System which allows you to build web applications and control every aspect of the content of your Continue reading

A Look at the New WordPress Brute Force Amplification Attack

Recently, a new brute force attack method for WordPress instances was identified by Sucuri. This latest technique allows attackers to try a large number of WordPress username and password login combinations in a single HTTP request.

The vulnerability can easily be abused by a simple script to try a significant number of username and password combinations with a relatively small number of HTTP requests. The following diagram shows a 4-fold increase in login attempts to HTTP requests, but this can trivially be expanded to a thousand logins.

WordPress XML-RPC Brute Force Amplification Attack

This form of brute force attack is harder to detect, since you won’t necessarily see a flood of requests. Fortunately, all CloudFlare paid customers have the option to enable a Web Application Firewall ruleset to stop this new attack method.

What is XML-RPC?

To understand the vulnerability, it’s important to understand the basics of the XML remote procedure protocol (XML-RPC).

XML-RPC uses XML encoding over HTTP to provide a remote procedure call protocol. It’s commonly used to execute various functions in a WordPress instance for APIs and other automated tasks. Requests that modify, manipulate, or view data using XML-RPC require user credentials with sufficient permissions.

Here is an example that requests a list Continue reading