Linux Exploit Mitigation
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Security Assurance Requirements for Linux Application Container Deployments
NISTIR 8176 Security Assurance Requirements for Linux Application Container Deployments Ramaswamy Chandramouli This publication is available free of charge from: https://doi.org/10.6028/NIST.IR.8176 NISTIR 8176 Security Assurance Requirements for Linux Application Container Deployments Ramaswamy Chandramouli Computer Security Division Information Technology Laboratory This publication is available free of charge from: https://doi.org/10.6028/NIST.IR.8176 October 2017 U.S. Department of Commerce Wilbur L. Ross, Jr., Secretary National Institute of Standards and Technology Walter Copan, NIST Director and Under Secretary of Commerce for Standards and Technology NISTIR 8176 SECURITY ASSURANCE FOR LINUX CONTAINERS National Institute of Standards and Technology Internal Report 8176 37 pages (October 2017) This publication is available free of charge from: https://doi.org/10.6028/NIST.IR.8176 Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by NIST, nor is it intended to imply that the entities, materials, or equipment are necessarily the best available for the purpose. This p There may be references in this publication to other publications currently under development by NIST in accordance with its assigned statutory responsibilities. The information in this publication, including concepts and methodologies, may be used by federal agencies even before the completion of such companion publications. Thus, until each ublication is available free of charge from: http publication is completed, current requirements, guidelines, and procedures, where they exist, remain operative. For planning and transition purposes, federal agencies may wish to closely follow the development of these new publications by NIST. -
Address Space Layout Permutation (ASLP): Towards Fine-Grained Randomization of Commodity Software
Address Space Layout Permutation (ASLP): Towards Fine-Grained Randomization of Commodity Software Chongkyung Kil,∗ Jinsuk Jun,∗ Christopher Bookholt,∗ Jun Xu,† Peng Ning∗ Department of Computer Science∗ Google, Inc.† North Carolina State University {ckil, jjun2, cgbookho, pning}@ncsu.edu [email protected] Abstract a memory corruption attack), an attacker attempts to alter program memory with the goal of causing that program to Address space randomization is an emerging and behave in a malicious way. The result of a successful at- promising method for stopping a broad range of memory tack ranges from system instability to execution of arbitrary corruption attacks. By randomly shifting critical memory code. A quick survey of US-CERT Cyber Security Alerts regions at process initialization time, address space ran- between mid-2005 and 2004 shows that at least 56% of the domization converts an otherwise successful malicious at- attacks have a memory corruption component [24]. tack into a benign process crash. However, existing ap- Memory corruption vulnerabilities are typically caused proaches either introduce insufficient randomness, or re- by the lack of input validation in the C programming lan- quire source code modification. While insufficient random- guage, with which the programmers are offered the free- ness allows successful brute-force attacks, as shown in re- dom to decide when and how to handle inputs. This flex- cent studies, the required source code modification prevents ibility often results in improved application performance. this effective method from being used for commodity soft- However, the number of vulnerabilities caused by failures ware, which is the major source of exploited vulnerabilities of input validation indicates that programming errors of this on the Internet. -
Security Enhancements in Red Hat Enterprise Linux (Beside Selinux)
Security Enhancements in Red Hat Enterprise Linux (beside SELinux) Ulrich Drepper Red Hat, Inc. [email protected] December 9, 2005 Abstract Bugs in programs are unavoidable. Programs developed using C and C++ are especially in danger. If bugs cannot be avoided the next best thing is to limit the damage. This article will show improvements in Red Hat Enterprise Linux which achieve just that. 1 Introduction These problems are harder to protect against since nor- mally2 all of the OS’s functionality is available and the Security problems are one of the biggest concerns in the attacker might even be able to use self-compiled code. industry today. Providing services on networked comput- ers which are accessible through the intranet and/or Inter- Remotely exploitable problems are more serious since net potentially to untrusted individuals puts the installa- the attacker can be anywhere if the machine is available tion at risk. A number of changes have been made to the through the Internet. On the plus side, only applications Linux OS1 which help a lot to mitigate the risks. Up- accessible through the network services provided by the coming Red Hat Enterprise Linux versions will feature machine can be exploited, which limits the range of ex- the SELinux extensions, originally developed by the Na- ploits. Further limitations are the attack vectors. Usually tional Security Agency (NSA), with whom Red Hat now remote attackers can influence applications only by pro- collaborates to productize the developed code. SELinux viding specially designed input. This often means cre- means a major change in Linux and is a completely sep- ating buffer overflows, i.e., situations where the data is arate topic by itself. -
Writing Kernel Exploits
Writing kernel exploits Keegan McAllister January 27, 2012 Keegan McAllister Writing kernel exploits Why attack the kernel? Total control of the system Huge attack surface Subtle code with potential for fun bugs Keegan McAllister Writing kernel exploits Kernel security Kernel and user code coexist in memory Kernel integrity depends on a few processor features: Separate CPU modes for kernel and user code Well-defined transitions between these modes Kernel-only instructions and memory Keegan McAllister Writing kernel exploits User vs. kernel exploits Typical userspace exploit: Manipulate someone's buggy program, locally or remotely Payload runs in the context of that user Typical kernel exploit: Manipulate the local kernel using system calls Payload runs in kernel mode Goal: get root! Remote kernel exploits exist, but are much harder to write Keegan McAllister Writing kernel exploits Scope We'll focus on the Linux kernel and 32-bit x86 hardware. Most ideas will generalize. References are on the last slides. Keegan McAllister Writing kernel exploits Let's see some exploits! We'll look at Two toy examples Two real exploits in detail Some others in brief How to harden your kernel Keegan McAllister Writing kernel exploits NULL dereference Keegan McAllister Writing kernel exploits A simple kernel module Consider a simple Linux kernel module. It creates a file /proc/bug1. It defines what happens when someone writes to that file. Keegan McAllister Writing kernel exploits bug1.c void (*my_funptr)(void); int bug1_write(struct file *file, const char *buf, unsigned long len) { my_funptr(); return len; } int init_module(void){ create_proc_entry("bug1", 0666, 0) ->write_proc = bug1_write; return 0; } Keegan McAllister Writing kernel exploits The bug $ echo foo > /proc/bug1 BUG: unable to handle kernel NULL pointer dereference Oops: 0000 [#1] SMP Pid: 1316, comm: bash EIP is at 0x0 Call Trace : [<f81ad009>] ? bug1_write+0x9/0x10 [bug1] [<c10e90e5>] ? proc_file_write+0x50/0x62 .. -
Telecom Sud Paris
Sécurité des OS et des systèmes Telecom Sud Paris Aurélien Wailly, Emmanuel Gras Amazon Dublin ANSSI Paris 2 Juin 2017 Présentation des intervenants Emmanuel Gras I Agence nationale de la sécurité des systèmes d’information depuis trop longtemps I Bureau inspections en SSI I http://pro.emmanuelgras.com I [email protected] Aurélien Wailly I Amazon depuis 2 ans I Thèse : End-to-end Security Architecture and Self-Protection Mechanisms for Cloud Computing Environments I Sécurité OS, reverse-engineering, réponse à incidents I http://aurelien.wail.ly I [email protected] A. Wailly, E. Gras (Amazon / ANSSI) Sécurité des OS et des systèmes 2 Juin 2017 2 / 259 Sécurité des sysèmes et des OS Objectifs I Fonctionnement des OS modernes, notamment du point de vue de la sécurité I Failles, exploitation, compromission I Dans le domaine de la sécurité, il est indispensable de comprendre comment marche un système pour l’exploiter Cibles I Linux, les principes restent valables pour les UNIX I Windows A. Wailly, E. Gras (Amazon / ANSSI) Sécurité des OS et des systèmes 2 Juin 2017 3 / 259 Plan 1 Introduction 2 OS, CPU et sécurité 3 Mémoire, segmentation et pagination (et sécurité !) 4 Sécurité des utilisateurs - UNIX 5 Sécurité des utilisateurs - Windows 6 Analyse de binaires - Concepts et outils 7 Failles applicatives 8 Protection des OS A. Wailly, E. Gras (Amazon / ANSSI) Sécurité des OS et des systèmes 2 Juin 2017 4 / 259 Votre OS ? www.dilbert.com/ A. Wailly, E. Gras (Amazon / ANSSI) Sécurité des OS et des systèmes 2 Juin 2017 5 / 259 Ce qui ne sera pas abordé La sécurité est un sujet vaste ! Réseau Virus et malwares Techniques logicielles avancées I Shellcoding poussé I Protection logicielle Exploitation Web I Cross Site Scripting I Injections SQL A. -
Linux-Professional-Institute-LPI-303
LPIC-3: Linux Enterprise Professional Certification LPIC-3 303: Security LPIC-3 is a professional certification program program that covers enterprise Linux specialties. LPIC-3 303 covers administering Linux enterprise-wide with an emphasis on Security. To become LPIC-3 certified, a candidate with an active LPIC-1 and LPIC-2 certification must pass at least one of the following specialty exams. Upon successful completion of the requirements, they will be entitled to the specialty designation: LPIC-3 Specialty Name. For example, LPIC-3 Virtualization & High Availability. Specialties: • 300: Mixed Environment • 303: Security • 304: Virtualization and High Availability TOPIC 325: CRYPTOGRAPHY • Configure Apache HTTPD with mod_ssl to that performs DNSSEC validation on behalf of 325.1 X.509 Certificates and Public Key provide HTTPS service, including SNI and its clients Infrastructures (5) HSTS • Key Signing Key, Zone Signing Key, Key Tag Candidates should understand X.509 certificates • Configure Apache HTTPD with mod_ssl to • Key generation, key storage, key management and public key infrastructures. They should know authenticate users using certificates and key rollover how to configure and use OpenSSL to implement • Configure Apache HTTPD with mod_ssl to • Maintenance and re-signing of zones certification authorities and issue SSL certificates provide OCSP stapling • Use DANE to publish X.509 certificate for various purposes. • Use OpenSSL for SSL/TLS client and server information in DNS Key knowledge areas: tests • Use TSIG for secure communication with BIND • Understand X.509 certificates, X.509 certificate 325.3 Encrypted File Systems (3) TOPIC 326: HOST SECURITY lifecycle, X.509 certificate fields and X.509v3 Candidates should be able to setup and 326.1 Host Hardening (3) certificate extensions configure encrypted file systems. -
A Buffer Overflow Study
A Bu®er Overflow Study Attacks & Defenses Pierre-Alain FAYOLLE, Vincent GLAUME ENSEIRB Networks and Distributed Systems 2002 Contents I Introduction to Bu®er Overflows 5 1 Generalities 6 1.1 Process memory . 6 1.1.1 Global organization . 6 1.1.2 Function calls . 8 1.2 Bu®ers, and how vulnerable they may be . 10 2 Stack overflows 12 2.1 Principle . 12 2.2 Illustration . 12 2.2.1 Basic example . 13 2.2.2 Attack via environment variables . 14 2.2.3 Attack using gets . 16 3 Heap overflows 18 3.1 Terminology . 18 3.1.1 Unix . 18 3.1.2 Windows . 18 3.2 Motivations and Overview . 18 3.3 Overwriting pointers . 19 3.3.1 Di±culties . 20 3.3.2 Interest of the attack . 20 3.3.3 Practical study . 20 3.4 Overwriting function pointers . 24 3.4.1 Pointer to function: short reminder . 24 3.4.2 Principle . 24 3.4.3 Example . 25 3.5 Trespassing the heap with C + + . 28 3.5.1 C++ Background . 28 3.5.2 Overwriting the VPTR . 31 3.5.3 Conclusions . 32 3.6 Exploiting the malloc library . 33 3.6.1 DLMALLOC: structure . 33 3.6.2 Corruption of DLMALLOC: principle . 34 II Protection solutions 37 4 Introduction 38 1 5 How does Libsafe work? 39 5.1 Presentation . 39 5.2 Why are the functions of the libC unsafe ? . 39 5.3 What does libsafe provide ? . 40 6 The Grsecurity Kernel patch 41 6.1 Open Wall: non-executable stack . -
6.2 Release Notes
Red Hat Enterprise Linux 6 6.2 Release Notes Release Notes for Red Hat Enterprise Linux 6.2 Edition 2 Last Updated: 2017-10-24 Red Hat Enterprise Linux 6 6.2 Release Notes Release Notes for Red Hat Enterprise Linux 6.2 Edition 2 Red Hat Engineering Content Services Legal Notice Copyright © 2011 Red Hat, Inc. This document is licensed by Red Hat under the Creative Commons Attribution-ShareAlike 3.0 Unported License. If you distribute this document, or a modified version of it, you must provide attribution to Red Hat, Inc. and provide a link to the original. If the document is modified, all Red Hat trademarks must be removed. Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law. Red Hat, Red Hat Enterprise Linux, the Shadowman logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries. Linux ® is the registered trademark of Linus Torvalds in the United States and other countries. Java ® is a registered trademark of Oracle and/or its affiliates. XFS ® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries. MySQL ® is a registered trademark of MySQL AB in the United States, the European Union and other countries. Node.js ® is an official trademark of Joyent. Red Hat Software Collections is not formally related to or endorsed by the official Joyent Node.js open source or commercial project. -
Chapter 10 Buffer Overflow Buffer Overflow
Chapter 10 Buffer Overflow Buffer Overflow ● Common attack mechanism ○ first wide use by the Morris Worm in 1988 ● Prevention techniques known ○ NX bit, stack canaries, ASLR ● Still of major concern ○ Recent examples: Shellshock, Hearthbleed Buffer Overflow/Buffer Overrun Definition: A condition at an interface under which more input can be placed into a buffer or data holding area than the capacity allocated, overwriting other information. Attackers exploit such a condition to crash a system or to insert specially crafted code that allows them to gain control of the system. Buffer Overflow Basics ● Programming error when a process attempts to store data beyond the limits of a fixed-sized buffer ● Overwrites adjacent memory locations ○ locations may hold other program variables, parameters, or program control flow data ○ buffer could be located on the stack, in the heap, or in the data section of the process ● Consequences: ○ corruption of program data ○ unexpected transfer of control ○ memory access violations Basic Buffer Overflow Example Basic Buffer Overflow Stack Values Buffer Overflow Attacks Attacker needs: ● To identify a buffer overflow vulnerability in some program that can be triggered using externally sourced data under the attacker’s control ● To understand how that buffer is stored in memory and determine potential for corruption Identifying vulnerable programs can be done by: ● inspection of program source ● tracing the execution of programs as they process oversized input ● using tools such as fuzzing to automatically identify -
Towards Efficient Heap Overflow Discovery
Towards Efficient Heap Overflow Discovery Xiangkun Jia, TCA/SKLCS, Institute of Software, Chinese Academy of Sciences; Chao Zhang, Institute for Network Science and Cyberspace, Tsinghua University; Purui Su, Yi Yang, Huafeng Huang, and Dengguo Feng, TCA/SKLCS, Institute of Software, Chinese Academy of Sciences https://www.usenix.org/conference/usenixsecurity17/technical-sessions/presentation/jia This paper is included in the Proceedings of the 26th USENIX Security Symposium August 16–18, 2017 • Vancouver, BC, Canada ISBN 978-1-931971-40-9 Open access to the Proceedings of the 26th USENIX Security Symposium is sponsored by USENIX Towards Efficient Heap Overflow Discovery Xiangkun Jia1;3, Chao Zhang2 , Purui Su1;3 , Yi Yang1, Huafeng Huang1, Dengguo Feng1 1TCA/SKLCS, Institute of Software, Chinese Academy of Sciences 2Institute for Network Science and Cyberspace 3University of Chinese Academy of Sciences Tsinghua University {jiaxiangkun, yangyi, huanghuafeng, feng}@tca.iscas.ac.cn [email protected] [email protected] Abstract to attack. As the heap layout is not deterministic, heap Heap overflow is a prevalent memory corruption vulner- overflow vulnerabilities are in general harder to exploit ability, playing an important role in recent attacks. Find- than stack corruption vulnerabilities. But attackers could ing such vulnerabilities in applications is thus critical for utilize techniques like heap spray [16] and heap feng- security. Many state-of-art solutions focus on runtime shui [43] to arrange the heap layout and reliably launch detection, requiring abundant inputs to explore program attacks, making heap overflow a realistic threat. paths in order to reach a high code coverage and luckily Several solutions are proposed to protect heap overflow trigger security violations. -
New Security Enhancements in Red Hat Enterprise Linux V.3, Update 3
New Security Enhancements in Red Hat Enterprise Linux v.3, update 3 By Arjan van de Ven Abstract This whitepaper describes the new security features that have been added to update 3 of Red Hat Enterprise Linux v.3: ExecShield and support for NX technology. August 2004 Table of Contents Introduction 2 Types of Security Holes 2 Buffer Overflows 3 Countering Buffer Overflows 4 Randomization 6 Remaining Randomization: PIE Binaries 7 Compatibility 8 How Well Does it Work? 9 Future Work 10 ¢¡¤£¦¥¨§ © ¤ ¦ ¨¢ ¨ ! ¨! "¨ $#!© ¨%¦&¨¦ ¨! ¤' ¨¡(*)+¤-, ¡ ¡¤.!+ !£§ ¡¤%/ 01, © 02 ".§ + § ¨.)+.§ 3¦01¡.§4§ .© 02 .§ + § ¨.)+.§ 3¦01¡54¢! . !! !© 6¢'7.!"¡ .§.8¡.%¨¦ § © ¨0 #© %8&9© 0:§ ¨ ¨© 02 .§ ¨+ § ¨.)+¤§ 3;¡!54#!© %!0;<=¡.§ >!¨, ¨0 ¦?@BA$¨C.6B'ED8F ! Introduction The world of computer security has changed dramatically in the last few years. Network security used to be about one dedicated hacker trying to get into one government computer, but now it is often about automated mass attacks. The SQL Slammer and Code Red worms were the first wide-scale computer security incidents to get mainstream press coverage. Linux has had similar, less-invasive worms in the past, such as the Slapper worm of 2002. Another relatively new phenomenon is that compromised computers are primarily being used for other purposes, including sending spam or participating in Distributed Denial of Service (DDOS) attacks. A contributing factor to the mass-compromise problem is that a large portion1 of users and system administrators generally do not apply the security fixes that are provided by the operating system vendor. This leaves a significant number of vulnerable machines connected to the Internet at all times. Providing security updates after the fact, however, is not sufficient. -
A Study of Gaps in Attack Analysis 5B
This report is the result of studies performed at Lincoln Laboratory, a federally funded research and development center operated by Massachusetts Institute of Technology. This material is based on work supported by the Department of Defense under Air Force Contract No. FA8721-05-C-0002 and/or FA8702-15-D-0001. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the Department of Defense. © 2016 MASSACHUSETTS INSTITUTE OF TECHNOLOGY Delivered to the U.S. Government with Unlimited Rights, as defined in DFARS Part 252.227-7013 or 7014 (Feb 2014). Notwithstanding any copyright notice, U.S. Government rights in this work are defined by DFARS 252.227-7013 or DFARS 252.227-7014 as detailed above. Use of this work other than as specifically authorized by the U.S. Government may violate any copyrights that exist in this work. This page intentionally left blank. EXECUTIVE SUMMARY The ability of the defender to detect and identify cyber attacks reflects the \arms race" na- ture of the cyber domain. While defenders develop new and improved techniques to detect known attacks, attackers resort to more sophisticated and stealthy techniques to perform their intrusions and evade detection. In this study, we identify the major gaps that exist in today's attack detection systems and infrastructures that impede more efficient and effective attack analysis. Attack anal- ysis in this study refers to activities related to identification and understanding of attack methods and techniques, the capability to detect such attacks in USG, DoD, and general enterprise systems, the ability to attribute such attacks to adversaries, and the ability to predict them before they happen.