Security threats Toolkit

OpenSSL shuts attack holes

Published: 18 Mar 2004 08:30 GMT

The group behind OpenSSL, a widely used open-source Web security program, released two patches for security flaws to block potential denial-of-service attacks, the organisation's developers said on Wednesday.

The flaws affect more than Linux systems that have the software installed. They could also hobble many routers and network devices that incorporate the software. Cisco Systems released an advisory on Wednesday, saying its PIX firewall devices and some routers could be affected.

OpenSSL is an open implementation of Secure Sockets Layer (SSL) encryption, which is used by almost all Web browsers as a way to secure data that travels over the public Internet. The software also forms the basis of a popular component of the Apache Web server, which accounts for more than two-thirds of the servers on the Internet.

The flaws don't give an attacker the opportunity to take control of a computer or a device, but they do create the possibility for specially crafted data to crash the software. Such a denial-of-service attack could stop users from logging in to a server and prevent administrators from managing network devices. In some cases, the flaws will crash the device, causing wider network outages, according to several advisories.

A survey conducted last November found that nearly half of the Web servers involved in the study ran a version of OpenSSL that hadn't been recently patched. A flaw in the Web server component based of OpenSSL was responsible for allowing the Linux Slapper worm to spread in September 2002.

Red Hat and Novell's SuSE Linux subsidiary both ship Linux systems that incorporate OpenSSL.