Welcome!

Linux Containers Authors: Yeshim Deniz, Pat Romanski, Elizabeth White, Amit Gupta, Liz McMillan

Related Topics: Linux Containers

Linux Containers: Article

Linux Kernel Vulnerability Found...and Fixed

Linux Kernel Vulnerability Found...and Fixed

Paul Starzetz and Wojciech Purczynski of ISEC Security Research compiled an advisory, released today.

"The exploitability of the discovered vulnerability is possible, although not a trivial one," they state. "We have identified at least two different attack vectors for the 2.4 kernel series. All users are encouraged to patch all vulnerable systems as soon as appropriate vendor patches are released."

Here is the advisory verbatim:

Synopsis: Linux kernel do_mremap local privilege escalation vulnerability
Product: Linux kernel
Version: 2.2, 2.4 and 2.6 series

Vendor: http://www.kernel.org/
URL: http://isec.pl/vulnerabilities/isec-0013-mremap.txt
CVE: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0985
Author: Paul Starzetz ,
Wojciech Purczynski
Date: January 5, 2004

Issue:
======

A critical security vulnerability has been found in the Linux kernel
memory management code in mremap(2) system call due to incorrect bound
checks.

Details:
========

The mremap system call provides functionality of resizing (shrinking or
growing) as well as moving across process's addressable space of existing
virtual memory areas (VMAs) or any of its parts.

A typical VMA covers at least one memory page (which is exactly 4kB on
the i386 architecture). An incorrect bound check discovered inside the
do_mremap() kernel code performing remapping of a virtual memory area
may lead to creation of a virtual memory area of 0 bytes length.

The problem bases on the general mremap flaw that remapping of 2 pages
from inside a VMA creates a memory hole of only one page in length but
an additional VMA of two pages. In the case of a zero sized remapping
request no VMA hole is created but an additional VMA descriptor of 0
bytes in length is created.

Such a malicious virtual memory area may disrupt the operation of other
parts of the kernel memory management subroutines finally leading to
unexpected behavior.

A typical process's memory layout showing invalid VMA created with
mremap system call:

08048000-0804c000 r-xp 00000000 03:05 959142 /tmp/test
0804c000-0804d000 rw-p 00003000 03:05 959142 /tmp/test
0804d000-0804e000 rwxp 00000000 00:00 0
40000000-40014000 r-xp 00000000 03:05 1544523 /lib/ld-2.3.2.so
40014000-40015000 rw-p 00013000 03:05 1544523 /lib/ld-2.3.2.so
40015000-40016000 rw-p 00000000 00:00 0
4002c000-40158000 r-xp 00000000 03:05 1544529 /lib/libc.so.6
40158000-4015d000 rw-p 0012b000 03:05 1544529 /lib/libc.so.6
4015d000-4015f000 rw-p 00000000 00:00 0
[*] 60000000-60000000 rwxp 00000000 00:00 0
bfffe000-c0000000 rwxp fffff000 00:00 0

The broken VMA in the above example has been marked with a [*].

Impact:
=======

Since no special privileges are required to use the mremap(2) system
call any process may misuse its unexpected behavior to disrupt the kernel
memory management subsystem. Proper exploitation of this vulnerability may
lead to local privilege escalation including execution of arbitrary code
with kernel level access. Proof-of-concept exploit code has been created
and successfully tested giving UID 0 shell on vulnerable systems.

The exploitability of the discovered vulnerability is possible, although
not a trivial one. We have identified at least two different attack
vectors for the 2.4 kernel series. All users are encouraged to patch all
vulnerable systems as soon as appropriate vendor patches are released.

Credits:
========

Paul Starzetz has identified the vulnerability and
performed further research.

Disclaimer:
===========

This document and all the information it contains are provided "as is",
for educational purposes only, without warranty of any kind, whether
express or implied.

The authors reserve the right not to be responsible for the topicality,
correctness, completeness or quality of the information provided in
this document. Liability claims regarding damage caused by the use of
any information provided, including any kind of information which is
incomplete or incorrect, will therefore be rejected.

More Stories By Linux News Desk

SYS-CON's Linux News Desk gathers stories, analysis, and information from around the Linux world and synthesizes them into an easy to digest format for IT/IS managers and other business decision-makers.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
SYS-CON Events announced today that Daiya Industry will exhibit at the Japanese Pavilion at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Ruby Development Inc. builds new services in short period of time and provides a continuous support of those services based on Ruby on Rails. For more information, please visit https://github.com/RubyDevInc.
SYS-CON Events announced today that CAST Software will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CAST was founded more than 25 years ago to make the invisible visible. Built around the idea that even the best analytics on the market still leave blind spots for technical teams looking to deliver better software and prevent outages, CAST provides the software intelligence that matter ...
As businesses evolve, they need technology that is simple to help them succeed today and flexible enough to help them build for tomorrow. Chrome is fit for the workplace of the future — providing a secure, consistent user experience across a range of devices that can be used anywhere. In her session at 21st Cloud Expo, Vidya Nagarajan, a Senior Product Manager at Google, will take a look at various options as to how ChromeOS can be leveraged to interact with people on the devices, and formats th...
SYS-CON Events announced today that Yuasa System will exhibit at the Japan External Trade Organization (JETRO) Pavilion at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Yuasa System is introducing a multi-purpose endurance testing system for flexible displays, OLED devices, flexible substrates, flat cables, and films in smartphones, wearables, automobiles, and healthcare.
SYS-CON Events announced today that Dasher Technologies will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Dasher Technologies, Inc. ® is a premier IT solution provider that delivers expert technical resources along with trusted account executives to architect and deliver complete IT solutions and services to help our clients execute their goals, plans and objectives. Since 1999, we'v...
Enterprises have taken advantage of IoT to achieve important revenue and cost advantages. What is less apparent is how incumbent enterprises operating at scale have, following success with IoT, built analytic, operations management and software development capabilities – ranging from autonomous vehicles to manageable robotics installations. They have embraced these capabilities as if they were Silicon Valley startups. As a result, many firms employ new business models that place enormous impor...
SYS-CON Events announced today that Massive Networks, that helps your business operate seamlessly with fast, reliable, and secure internet and network solutions, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. As a premier telecommunications provider, Massive Networks is headquartered out of Louisville, Colorado. With years of experience under their belt, their team of...
SYS-CON Events announced today that Taica will exhibit at the Japan External Trade Organization (JETRO) Pavilion at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Taica manufacturers Alpha-GEL brand silicone components and materials, which maintain outstanding performance over a wide temperature range -40C to +200C. For more information, visit http://www.taica.co.jp/english/.
SYS-CON Events announced today that TidalScale, a leading provider of systems and services, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. TidalScale has been involved in shaping the computing landscape. They've designed, developed and deployed some of the most important and successful systems and services in the history of the computing industry - internet, Ethernet, operating s...
SYS-CON Events announced today that MIRAI Inc. will exhibit at the Japan External Trade Organization (JETRO) Pavilion at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. MIRAI Inc. are IT consultants from the public sector whose mission is to solve social issues by technology and innovation and to create a meaningful future for people.
SYS-CON Events announced today that IBM has been named “Diamond Sponsor” of SYS-CON's 21st Cloud Expo, which will take place on October 31 through November 2nd 2017 at the Santa Clara Convention Center in Santa Clara, California.
SYS-CON Events announced today that TidalScale will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. TidalScale is the leading provider of Software-Defined Servers that bring flexibility to modern data centers by right-sizing servers on the fly to fit any data set or workload. TidalScale’s award-winning inverse hypervisor technology combines multiple commodity servers (including their ass...
Join IBM November 1 at 21st Cloud Expo at the Santa Clara Convention Center in Santa Clara, CA, and learn how IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Cognitive analysis impacts today’s systems with unparalleled ability that were previously available only to manned, back-end operations. Thanks to cloud processing, IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Imagine a robot vacuum that becomes your personal assistant tha...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
As popularity of the smart home is growing and continues to go mainstream, technological factors play a greater role. The IoT protocol houses the interoperability battery consumption, security, and configuration of a smart home device, and it can be difficult for companies to choose the right kind for their product. For both DIY and professionally installed smart homes, developers need to consider each of these elements for their product to be successful in the market and current smart homes.
Infoblox delivers Actionable Network Intelligence to enterprise, government, and service provider customers around the world. They are the industry leader in DNS, DHCP, and IP address management, the category known as DDI. We empower thousands of organizations to control and secure their networks from the core-enabling them to increase efficiency and visibility, improve customer service, and meet compliance requirements.
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend 21st Cloud Expo October 31 - November 2, 2017, at the Santa Clara Convention Center, CA, and June 12-14, 2018, at the Javits Center in New York City, NY, and learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
Most technology leaders, contemporary and from the hardware era, are reshaping their businesses to do software. They hope to capture value from emerging technologies such as IoT, SDN, and AI. Ultimately, irrespective of the vertical, it is about deriving value from independent software applications participating in an ecosystem as one comprehensive solution. In his session at @ThingsExpo, Kausik Sridhar, founder and CTO of Pulzze Systems, will discuss how given the magnitude of today's applicati...
Smart cities have the potential to change our lives at so many levels for citizens: less pollution, reduced parking obstacles, better health, education and more energy savings. Real-time data streaming and the Internet of Things (IoT) possess the power to turn this vision into a reality. However, most organizations today are building their data infrastructure to focus solely on addressing immediate business needs vs. a platform capable of quickly adapting emerging technologies to address future ...
SYS-CON Events announced today that mruby Forum will exhibit at the Japan External Trade Organization (JETRO) Pavilion at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. mruby is the lightweight implementation of the Ruby language. We introduce mruby and the mruby IoT framework that enhances development productivity. For more information, visit http://forum.mruby.org/.