The linux-2.4.21-mlock.patch in Red Hat Enterprise Linux 3 does not properly maintain the mlock page count when one process unlocks pages that belong to another process, which allows local users to mlock more memory than specified by the rlimit.

Updated kernel packages that fix several security issues in the Red Hat Enterprise Linux 3 kernel are now available.

This security advisory has been rated as having important security impact by the Red Hat Security Response Team.

The Linux kernel handles the basic functions of the operating system.

These new kernel packages contain fixes for the three security issues described below as well as an important fix for a problem that could lead to data corruption on x86-architecture SMP systems with greater than 4GB of memory through heavy usage of multi-threaded applications.

A flaw between execve() syscall handling and core dumping of ELF-format executables allowed local unprivileged users to cause a denial of service (system crash) or possibly gain privileges. The Common Vulnerabilities and Exposures project has assigned the name CVE-2005-1263 to this issue.

A flaw in shared memory locking allowed local unprivileged users to lock and unlock regions of shared memory segments they did not own (CVE-2005-0176).

A flaw in the locking of SysV IPC shared memory regions allowed local unprivileged users to bypass their RLIMIT_MEMLOCK resource limit (CVE-2004-0491).

Note: The kernel-unsupported package contains various drivers and modules that are unsupported and therefore might contain security problems that have not been addressed.

All Red Hat Enterprise Linux 3 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

Please also consult the RHEL3 Update 5 advisory RHSA-2005:294 for the complete list of features added and bugs fixed in U5, which was released only a week prior to this security update.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2005-472.

ID	Name	Product	Family	Severity
21828	CentOS 3 : kernel (CESA-2005:472)	Nessus	CentOS Local Security Checks	high
18389	RHEL 3 : kernel (RHSA-2005:472)	Nessus	Red Hat Local Security Checks	high
801408	CentOS RHSA-2005-472 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2004-0491

critical

Tenable Plugins

high

high

high