Programmers disclosed a security hole this week in a part of the heart of the Linux operating system that could let users of a machine take it over even if they don't have privileges to do so.
The vulnerability affects both the 2.2 and 2.4 series of Linux kernels, the core of the operating system, said Alan Cox, one of the key deputies of Linux founder Linus Torvalds in the programming community that collectively produces Linux. Those kernels are at the center of several Linux products released recently from companies such as Red Hat and SuSE.

Cox submitted a patch to fix the problem Monday. Top Linux seller Red Hat posted a patch for the vulnerability on Monday.

The problem could let "local" computer users--those with permission to log on to a machine--to gain "root" access and take complete control of the machine, Cox said. Such "local" vulnerabilities are considered less severe than "remote" ones that let attackers over a network take over a machine even if they don't have a basic user account on it.

The problem affected the "ptrace" component of Linux, which is used to help find bugs in software.

A recent spate of security problems have cropped up in several open-source programs. Earlier this week, programmers disclosed a vulnerability in the Samba package used to share files between Windows, Linux and Unix systems that could let attackers across a network take over a computer. And another problem in the Sendmail e-mail server software also led to the possibility of network-based attacks.