Unknown vulnerability in Linux kernel 2.x may allow local users to modify the group ID of files, such as NFS exported files in kernel 2.4.

The remote host is affected by the vulnerability described in GLSA-200407-16 (Linux Kernel: Multiple DoS and permission vulnerabilities)

    The Linux kernel allows a local attacker to mount a remote file system     on a vulnerable Linux host and modify files' group IDs. On 2.4 series     kernels this vulnerability only affects shared NFS file systems. This     vulnerability has been assigned CAN-2004-0497 by the Common     Vulnerabilities and Exposures project.
    Also, a flaw in the handling of /proc attributes has been found in 2.6     series kernels; allowing the unauthorized modification of /proc     entries, especially those which rely solely on file permissions for     security to vital kernel parameters.
    An issue specific to the VServer Linux sources has been found, by which     /proc related changes in one virtual context are applied to other     contexts as well, including the host system.
    CAN-2004-0447 resolves a local DoS vulnerability on IA64 platforms     which can cause unknown behaviour and CAN-2004-0565 resolves a floating     point information leak on IA64 platforms by which registers of other     processes can be read by a local user.
    Finally, CAN-2004-0496 addresses some more unknown vulnerabilities in     2.6 series Linux kernels older than 2.6.7 which were found by the     Sparse source code checking tool.
  Impact :

    Bad Group IDs can possibly cause a Denial of Service on parts of a host     if the changed files normally require a special GID to properly     operate. By exploiting this vulnerability, users in the original file     group would also be blocked from accessing the changed files.
    The /proc attribute vulnerability allows local users with previously no     permissions to certain /proc entries to exploit the vulnerability and     then gain read, write and execute access to entries.
    These new privileges can be used to cause unknown behaviour ranging     from reduced system performance to a Denial of Service by manipulating     various kernel options which are usually reserved for the superuser.
    This flaw might also be used for opening restrictions set through /proc     entries, allowing further attacks to take place through another     possibly unexpected attack vector.
    The VServer issue can also be used to induce similar unexpected     behaviour to other VServer contexts, including the host. By successful     exploitation, a Denial of Service for other contexts can be caused     allowing only root to read certain /proc entries. Such a change would     also be replicated to other contexts, forbidding normal users on those     contexts to read /proc entries which could contain details needed by     daemons running as a non-root user, for example.
    Additionally, this vulnerability allows an attacker to read information     from another context, possibly hosting a different server, gaining     critical information such as what processes are running. This may be     used for furthering the exploitation of either context.
    CAN-2004-0447 and CAN-2004-0496 permit various local unknown Denial of     Service vulnerabilities with unknown impacts - these vulnerabilities     can be used to possibly elevate privileges or access reserved kernel     memory which can be used for further exploitation of the system.
    CAN-2004-0565 allows FPU register values of other processes to be read     by a local user setting the MFH bit during a floating point operation -     since no check was in place to ensure that the FPH bit was owned by the     requesting process, but only an MFH bit check, an attacker can simply     set the MFH bit and access FPU registers of processes running as other     users, possibly those running as root.
  Workaround :

    2.4 users may not be affected by CAN-2004-0497 if they do not use     remote network filesystems and do not have support for any such     filesystems in their kernel configuration. All 2.6 users are affected     by the /proc attribute issue and the only known workaround is to     disable /proc support. The VServer flaw applies only to     vserver-sources, and no workaround is currently known for the issue.
    There is no known fix to CAN-2004-0447, CAN-2004-0496 or CAN-2004-0565     other than to upgrade the kernel to a patched version.
    As a result, all users affected by any of these vulnerabilities should     upgrade their kernels to ensure the integrity of their systems.

A number of vulnerabilities were discovered in the Linux kernel that are corrected with this update :

Multiple vulnerabilities were found by the Sparse source checker that could allow local users to elevate privileges or gain access to kernel memory (CVE-2004-0495).

Missing Discretionary Access Controls (DAC) checks in the chown(2) system call could allow an attacker with a local account to change the group ownership of arbitrary files, which could lead to root privileges on affected systems (CVE-2004-0497).

An information leak vulnerability that affects only ia64 systems was fixed (CVE-2004-0565).

Insecure permissions on /proc/scsi/qla2300/HbaApiNode could allow a local user to cause a DoS on the system; this only affects Mandrakelinux 9.2 and below (CVE-2004-0587).

A vulnerability that could crash the kernel has also been fixed. This crash, however, can only be exploited via root (in br_if.c).

The provided packages are patched to fix these vulnerabilities. All users are encouraged to upgrade to these updated kernels.

To update your kernel, please follow the directions located at :

http://www.mandrakesoft.com/security/kernelupdate

The remote host is missing the patch for the advisory SUSE-SA:2004:020 (kernel).


Multiple security vulnerabilities are being addressed with this security update of the Linux kernel.

Kernel memory access vulnerabilities are fixed in the e1000, decnet, acpi_asus, alsa, airo/WLAN, pss and mpu401 drivers. These vulnerabilities can lead to kernel memory read access, write access and local denial of service conditions, resulting in access to the root account for an attacker with a local account on the affected system.

Missing Discretionary Access Control (DAC) checks in the chown(2) system call allow an attacker with a local account to change the group ownership of arbitrary files, which leads to root privileges on affected systems. It is specific to kernel version 2.6 based systems such as the SUSE Linux 9.1 product, that only local shell access is needed to exploit this vulnerability. An interesting variant of the missing checks is that the ownership of files in the /proc filesystem can be altered, while the changed ownership still does not allow the files to be accessed as a non-root user for to be able to exploit the vulnerability. Systems that are based on a version 2.4 kernel are not vulnerable to the /proc weakness, and exploitation of the weakness requires the use of the kernel NFS server (knfsd). If the knfsd NFS server is not activated (it is off by default), the vulnerability is not exposed. These issues related to the chown(2) system call have been discovered by Michael Schroeder and Ruediger Oertel, both SUSE LINUX.

The only network-related vulnerability fixed with the kernel updates that are subject to this announcement affect the SUSE Linux 9.1 distribution only, as it is based on a 2.6 kernel. Found and reported to bugtraq by Adam Osuchowski and Tomasz Dubinski, the vulnerability allows a remote attacker to send a specially crafted TCP packet to a vulnerable system, causing that system to stall if it makes use of TCP option matching netfilter rules.

In some rare configurations of the SUSE Linux 9.1 distribution, some users have experienced stalling systems during system startup. These problems are fixed with this kernel update.

During an audit of the Linux kernel, SUSE discovered a flaw that allowed a user to make unauthorized changes to the group ID of files in certain circumstances. In the 2.4 kernel, as shipped with Fedora Core 1, the only way this could happen is through the kernel nfs server. A user on a system that mounted a remote file system from a vulnerable machine may be able to make unauthorized changes to the group ID of exported files. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0497 to this issue. Only Fedora Core 1 systems that are configured to share file systems via NFS are affected by this issue.

Additionally, a number of issues were discovered with the Broadcom 5820 driver. Until such time that these get fixed, this driver has been disabled.

All Fedora Core 1 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

During an audit of the Linux kernel, SUSE discovered a flaw in the Linux kernel that inappropriately allows an unprivileged user to change the group ID of a file to his/her own group ID. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0497 to this issue.

All Fedora Core 2 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Updated kernel packages that fix a security vulnerability affecting the kernel nfs server for Red Hat Enterprise Linux 3 are now available.

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

During an audit of the Linux kernel, SUSE discovered a flaw that allowed a user to make unauthorized changes to the group ID of files in certain circumstances. In the 2.4 kernel, as shipped with Red Hat Enterprise Linux, the only way this could happen is through the kernel nfs server. A user on a system that mounted a remote file system from a vulnerable machine may be able to make unauthorized changes to the group ID of exported files. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0497 to this issue.

Only Red Hat Enterprise Linux systems that are configured to share file systems via NFS are affected by this issue.

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.

Updated kernel packages that fix a security vulnerability affecting the kernel nfs server for Red Hat Enterprise Linux 2.1 are now available.

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

During an audit of the Linux kernel, SUSE discovered a flaw that allowed a user to make unauthorized changes to the group ID of files in certain circumstances. In the 2.4 kernel, as shipped with Red Hat Enterprise Linux, the only way this could happen is through the kernel nfs server. A user on a system that mounted a remote file system from a vulnerable machine may be able to make unauthorized changes to the group ID of exported files. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0497 to this issue.

Only Red Hat Enterprise Linux systems that are configured to share file systems via NFS are affected by this issue.

All Red Hat Enterprise Linux 2.1 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum. These packages contain a backported patch to correct this issue.

Updated kernel packages that fix a security vulnerability affecting
the kernel nfs server for Red Hat Enterprise Linux 3 are now
available.

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

During an audit of the Linux kernel, SUSE discovered a flaw that
allowed a user to make unauthorized changes to the group ID of files
in certain circumstances. In the 2.4 kernel, as shipped with Red Hat
Enterprise Linux, the only way this could happen is through the kernel
nfs server. A user on a system that mounted a remote file system from
a vulnerable machine may be able to make unauthorized changes to the
group ID of exported files. The Common Vulnerabilities and Exposures
project (cve.mitre.org) has assigned the name CVE-2004-0497 to this
issue.

Only Red Hat Enterprise Linux systems that are configured to share
file systems via NFS are affected by this issue.

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.

Updated kernel packages that fix a security vulnerability affecting
the kernel nfs server for Red Hat Enterprise Linux 2.1 are now
available.

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

During an audit of the Linux kernel, SUSE discovered a flaw that
allowed a user to make unauthorized changes to the group ID of files
in certain circumstances. In the 2.4 kernel, as shipped with Red Hat
Enterprise Linux, the only way this could happen is through the kernel
nfs server. A user on a system that mounted a remote file system from
a vulnerable machine may be able to make unauthorized changes to the
group ID of exported files. The Common Vulnerabilities and Exposures
project (cve.mitre.org) has assigned the name CVE-2004-0497 to this
issue.

Only Red Hat Enterprise Linux systems that are configured to share
file systems via NFS are affected by this issue.

All Red Hat Enterprise Linux 2.1 users are advised to upgrade their
kernels to the packages associated with their machine architectures
and configurations as listed in this erratum. These packages contain a
backported patch to correct this issue.

During an audit of the Linux kernel, SUSE discovered a flaw that
allowed a user to make unauthorized changes to the group ID of files
in certain circumstances. In the 2.4 kernel, as shipped with Fedora
Core 1, the only way this could happen is through the kernel nfs
server. A user on a system that mounted a remote file system from a
vulnerable machine may be able to make unauthorized changes to the
group ID of exported files. The Common Vulnerabilities and Exposures
project (cve.mitre.org) has assigned the name CVE-2004-0497 to this
issue. Only Fedora Core 1 systems that are configured to share file
systems via NFS are affected by this issue.

Additionally, a number of issues were discovered with the Broadcom
5820 driver. Until such time that these get fixed, this driver has
been disabled.

All Fedora Core 1 users are advised to upgrade their kernels to the
packages associated with their machine architectures and
configurations as listed in this erratum.

During an audit of the Linux kernel, SUSE discovered a flaw in the
Linux kernel that inappropriately allows an unprivileged user to
change the group ID of a file to his/her own group ID. The Common
Vulnerabilities and Exposures project (cve.mitre.org) has assigned the
name CVE-2004-0497 to this issue.

All Fedora Core 2 users are advised to upgrade their kernels to the
packages associated with their machine architectures and
configurations as listed in this erratum.

ID	Name	Product	Family	Severity
14549	GLSA-200407-16 : Linux Kernel: Multiple DoS and permission vulnerabilities	Nessus	Gentoo Local Security Checks	high
14165	Mandrake Linux Security Advisory : kernel (MDKSA-2004:066)	Nessus	Mandriva Local Security Checks	high
13836	SUSE-SA:2004:020: kernel	Nessus	SuSE Local Security Checks	high
13737	Fedora Core 1 : kernel-2.4.22-1.2197.nptl (2004-206)	Nessus	Fedora Local Security Checks	low
13736	Fedora Core 2 : kernel-2.6.6-1.435.2.3 (2004-205)	Nessus	Fedora Local Security Checks	low
12511	RHEL 3 : kernel (RHSA-2004:360)	Nessus	Red Hat Local Security Checks	low
12510	RHEL 2.1 : kernel (RHSA-2004:354)	Nessus	Red Hat Local Security Checks	low
801596	Red Hat 2004-360 Security Check	Log Correlation Engine	Generic	high
801595	Red Hat 2004-354 Security Check	Log Correlation Engine	Generic	high
801556	Fedora 2004-206 Security Check	Log Correlation Engine	Generic	high
801555	Fedora 2004-205 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2004-0497

medium

Tenable Plugins

high

high

high

low

low

low

low

high

high

high

high