Hewlett-Packard has confirmed that its HP-UX Unix operating system contains several serious security flaws which could allow attackers to disable or take control of a server, among other things.
The company is urging users of HP-UX versions B.11.00, B.11.11, B.11.22, and B.11.23 running the hpuxwsAPACHE HP-UX Apache-based Web server to solve the problem by upgrading. Procedures for identifying an affected system and upgrading are detailed in HP's advisory.
Separately, HP confirmed that a number of flaws in Apache affect HP VirtualVault and HP Webproxy, in advisories here and here. The bugs affect HP-UX release B.11.04 with VirtualVault A.04.50 - A.04.70 or Webproxy A.02.00 - A.02.10 installed, and users can protect themselves by upgrading to newer software versions.
The first set of problems were all identified and patched in various components of HP-UX by mid-July. One bug is in PHP, the most popular scripting module on Apache servers, which is enabled on at least half of all Apache servers, according to figures from SecuritySpace. The bug, involving various errors in PHP's memory_limit request termination, could be exploited to allow an attacker to execute arbitrary code on a server with a vulnerable implementation of PHP enabled, researchers said. The exploit works on any platform, according to a report by E-matters researcher Stefan Esser, who said he discovered the problem during a re-audit of memory_limit following a related advisory.
Another problem is in mod_ssl, which is widely used in Apache servers running OpenSSL to provide SSL and Transport Layer Security (TLS) protocol support - both important for e-commerce servers. According to the mod_ssl project, which disclosed the bug on 16 July along with a patch, the bug affects Apache 1.3.x and only affects servers running both mod_ssl and another module called mod_proxy. Under certain server configurations, a remote attacker could execute arbitrary code with the same privileges as Apache.
As for HP VirtualVault and HP Webproxy, the company listed five separate Apache flaws affecting the software, which could be exploited to cause a denial of service, bypass security restrictions, or compromise a vulnerable system, according to security researchers. The bugs are all at least several weeks old - one of them is the mod_ssl issue detailed above.