The OpenSSL Project confirmed that weak passwords used on the hosting infrastructure led to the compromise of its website, dispelling concerns that attackers might have exploited a vulnerability in virtualization software.
The home page of www.openssl.org, the official site the OpenSSL Project, was defaced Sunday to display a message from a group of hackers called TurkGuvenligi.
The incident caused concern among security experts because OpenSSL is a very popular cryptographic library that's used to implement secure communications in a wide variety of software products, from Web servers to mobile apps.
On Jan. 1, the OpenSSL Project published some preliminary findings following an initial investigation into the compromise and said that the integrity of the OpenSSL source code had not been affected.
"The source repositories have been checked and they were not affected," the OpenSSL Project said on its website. "Other than the modification to the index.html page no changes to the website had been made."
However, the preliminary report sparked new concerns because it also said the attack happened through the hypervisor of the hosting environment.
A hypervisor is a piece of software that's used to create and run virtual machines -- virtual instances of OS installations. In hosting environments hypervisors are commonly used to run multiple virtualized servers on the same physical machine; these are known as virtual private servers (VPS).
According to a DNS lookup for www.openssl.org, the site's hosting provider is a Swedish company called Indit Hosting whose VPS offerings run on the VMware ESXi and KVM hypervisors.
A serious vulnerability in VMware ESXi could have a far-reaching impact, given the product's popularity in hosting environments, so VMware immediately took an interest in the OpenSSL compromise.
"The VMware Security Response Center has actively investigated this incident with both the OpenSSL Foundation and their Hosting Provider in order to understand whether VMware products are implicated and whether VMware needs to take any action to ensure customer safety," the company said Thursday in a blog post. "We have no reason to believe that the OpenSSL website defacement is a result of a security vulnerability in any VMware products and that the defacement is a result of an operational security error."
The OpenSSL Project updated its own report Friday to clarify that the attack was not the result of a vulnerability in the hypervisor itself, but a result of the hosting provider using insecure passwords. This security oversight led to unauthorized control of the hypervisor management console which was then used to manipulate the virtual server hosting the OpenSSL website, the OpenSSL Project said.
Indit Hosting did not immediately respond to a request for comment, but the OpenSSL Project said that steps were taken to protect against this type of attack in the future.