RHEL 5 : kernel (RHSA-2016:2124) (Dirty COW)

high Nessus Plugin ID 94431

Synopsis

The remote Red Hat host is missing one or more security updates.

Description

An update for kernel is now available for Red Hat Enterprise Linux 5.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es) :

* A race condition was found in the way the Linux kernel's memory subsystem handled the copy-on-write (COW) breakage of private read-only memory mappings. An unprivileged, local user could use this flaw to gain write access to otherwise read-only memory mappings and thus increase their privileges on the system. (CVE-2016-5195, Important)

* It was found that stacking a file system over procfs in the Linux kernel could lead to a kernel stack overflow due to deep nesting, as demonstrated by mounting ecryptfs over procfs and creating a recursion by mapping /proc/environ. An unprivileged, local user could potentially use this flaw to escalate their privileges on the system.
(CVE-2016-1583, Important)

Red Hat would like to thank Phil Oester for reporting CVE-2016-5195.

Bug Fix(es) :

* In some cases, a kernel crash or file system corruption occurred when running journal mode 'ordered'. The kernel crash was caused by a NULL pointer dereference due to a race condition between two journal functions. The file system corruption occurred due to a race condition between the do_get_write_access() function and buffer writeout. This update fixes both race conditions. As a result, neither the kernel crash, nor the file system corruption now occur. (BZ#1067708)

* Prior to this update, some Global File System 2 (GFS2) files had incorrect time stamp values due to two problems with handling time stamps of such files. The first problem concerned the atime time stamp, which ended up with an arbitrary value ahead of the actual value, when a GFS2 file was accessed. The second problem was related to the mtime and ctime time stamp updates, which got lost when a GFS2 file was written to from one node and read from or written to from another node. With this update, a set of patches has been applied that fix these problems. As a result, the time stamps of GFS2 files are now handled correctly. (BZ#1374861)

Solution

Update the affected packages.

See Also

https://access.redhat.com/errata/RHSA-2016:2124

https://access.redhat.com/security/cve/cve-2016-5195

https://access.redhat.com/security/cve/cve-2016-1583

Plugin Details

Severity: High

ID: 94431

File Name: redhat-RHSA-2016-2124.nasl

Version: 2.16

Type: local

Agent: unix

Published: 10/31/2016

Updated: 3/8/2022

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.8

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6.3

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2016-5195

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:H/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-pae, p-cpe:/a:redhat:enterprise_linux:kernel-pae-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-pae-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:kernel-debug-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-debuginfo-common, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-doc, p-cpe:/a:redhat:enterprise_linux:kernel-headers, p-cpe:/a:redhat:enterprise_linux:kernel-kdump, p-cpe:/a:redhat:enterprise_linux:kernel-kdump-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-kdump-devel, p-cpe:/a:redhat:enterprise_linux:kernel-xen, p-cpe:/a:redhat:enterprise_linux:kernel-xen-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-xen-devel, cpe:/o:redhat:enterprise_linux:5

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/28/2016

CISA Known Exploited Vulnerability Due Dates: 3/24/2022

Exploitable With

CANVAS (CANVAS)

Core Impact

Reference Information

CVE: CVE-2016-1583, CVE-2016-5195

IAVA: 2016-A-0306-S

RHSA: 2016:2124