Running Untrusted Application Code: Sandboxing Running Untrusted Code
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Iocage Documentation Release 1.2
iocage Documentation Release 1.2 Brandon Schneider and Peter Toth Sep 26, 2019 Contents 1 Documentation: 3 1.1 Install iocage...............................................3 1.2 Basic Usage...............................................6 1.3 Plugins.................................................. 10 1.4 Networking................................................ 11 1.5 Jail Types................................................. 14 1.6 Best Practices............................................... 15 1.7 Advanced Usage............................................. 16 1.8 Using Templates............................................. 20 1.9 Create a Debian Squeeze Jail (GNU/kFreeBSD)............................ 21 1.10 Known Issues............................................... 22 1.11 FAQ.................................................... 23 1.12 Indices and tables............................................ 24 Index 25 i ii iocage Documentation, Release 1.2 iocage is a jail/container manager written in Python, combining some of the best features and technologies the FreeBSD operating system has to offer. It is geared for ease of use with a simplistic and easy to learn command syntax. FEATURES: • Templates, basejails, and normal jails • Easy to use • Rapid thin provisioning within seconds • Automatic package installation • Virtual networking stacks (vnet) • Shared IP based jails (non vnet) • Dedicated ZFS datasets inside jails • Transparent ZFS snapshot management • Binary updates • Export and import • And many more! Contents 1 iocage Documentation, -
Freebsd's Jail(2) Facility
Lousy virtualization, Happy users: FreeBSD's jail(2) facility Poul-Henning Kamp [email protected] CHROOT(2) FreeBSD System Calls Manual CHROOT(2) NAME chroot -- change root directory LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <unistd.h> int chroot(const char *dirname); Calling chroot(2) in ftpd(1) implemented ”anonymous FTP” without the hazzle of file/pathname parsing and editing. ”anonymous FTP” became used as a tool to enhance network security. By inference, chroot(2) became seen as a security enhancing feature. ...The source were not strong in those. Exercise 1: List at least four ways to escape chroot(2). Then the Internet happened, ...and web-servers, ...and web-hosting Virtual hosts in Apache User get their own ”virtual apache” but do do not get your own machine. Also shared: Databases mailprograms PHP/Perl etc. Upgrading tools (PHP, mySQL etc) on virtual hosting machines is a nightmare. A really bad nightmare: Cust#1 needs mySQL version > N Cust#2 cannot use mySQL version <M (unless PHP version > K) Cust#3 does not answer telephone Cust#4 has new sysadmin Cust#5 is just about ready with new version Wanted: Lightweight virtualization Same kernel, but virtual filesystem and network address plus root limitations. Just like chroot(2) with IP numbers on top. Will pay cash. Close holes in chroot(2) Introduce ”jail” syscall + kernel struct Block jailed root in most suser(9) calls. Check ”if jail, same jail ?” in strategic places. Fiddle socket syscall arguments: INADDR_ANY -> jail.ip INADDR_LOOPBACK -> jail.ip Not part of jail(2): Resource restriction Hardware virtualization Covert channel prevention (the hard stuff) Total implementation: 350 changed source lines 400 new lines of code FreeBSD without jail usr Resources of various sorts / home var process process process process process process Kernel FreeBSD with jail usr Resources of various sorts / home var process process process process* process process Kernel error = priv_check_cred( cred, PRIV_VFS_LINK, SUSER_ALLOWJAIL); if (error) return (error); The unjailed part One jailed part of the system. -
Making Linux Protection Mechanisms Egalitarian with Userfs
Making Linux Protection Mechanisms Egalitarian with UserFS Taesoo Kim and Nickolai Zeldovich MIT CSAIL ABSTRACT firewall rules, forcing applications to invent their own UserFS provides egalitarian OS protection mechanisms protection techniques like system call interposition [15], in Linux. UserFS allows any user—not just the system binary rewriting [30] or analysis [13, 45], or interposing administrator—to allocate Unix user IDs, to use chroot, on system accesses in a language runtime like Javascript. and to set up firewall rules in order to confine untrusted This paper presents the design of UserFS, a kernel code. One key idea in UserFS is representing user IDs as framework that allows any application to use traditional files in a /proc-like file system, thus allowing applica- OS protection mechanisms on a Unix system, and a proto- tions to manage user IDs like any other files, by setting type implementation of UserFS for Linux. UserFS makes permissions and passing file descriptors over Unix do- protection mechanisms egalitarian, so that any user—not main sockets. UserFS addresses several challenges in just the system administrator—can allocate new user IDs, making user IDs egalitarian, including accountability, re- set up firewall rules, and isolate processes using chroot. source allocation, persistence, and UID reuse. We have By using the operating system’s own protection mecha- ported several applications to take advantage of UserFS; nisms, applications can avoid race conditions and ambi- by changing just tens to hundreds of lines of code, we guities associated with system call interposition [14, 43], prevented attackers from exploiting application-level vul- can confine existing code without having to recompile or nerabilities, such as code injection or missing ACL checks rewrite it in a new language, and can enforce a coherent in a PHP-based wiki application. -
Sandboxing 2 Change Root: Chroot()
Sandboxing 2 Change Root: chroot() Oldest Unix isolation mechanism Make a process believe that some subtree is the entire file system File outside of this subtree simply don’t exist Sounds good, but. Sandboxing 2 2 / 47 Chroot Sandboxing 2 3 / 47 Limitations of Chroot Only root can invoke it. (Why?) Setting up minimum necessary environment can be painful The program to execute generally needs to live within the subtree, where it’s exposed Still vulnerable to root compromise Doesn’t protect network identity Sandboxing 2 4 / 47 Root versus Chroot Suppose an ordinary user could use chroot() Create a link to the sudo command Create /etc and /etc/passwd with a known root password Create links to any files you want to read or write Besides, root can escape from chroot() Sandboxing 2 5 / 47 Escaping Chroot What is the current directory? If it’s not under the chroot() tree, try chdir("../../..") Better escape: create device files On Unix, all (non-network) devices have filenames Even physical memory has a filename Create a physical memory device, open it, and change the kernel data structures to remove the restriction Create a disk device, and mount a file system on it. Then chroot() to the real root (On Unix systems, disks other than the root file system are “mounted” as a subtree somewhere) Sandboxing 2 6 / 47 Trying Chroot # mkdir /usr/sandbox /usr/sandbox/bin # cp /bin/sh /usr/sandbox/bin/sh # chroot /usr/sandbox /bin/sh chroot: /bin/sh: Exec format error # mkdir /usr/sandbox/libexec # cp /libexec/ld.elf_so /usr/sandbox/libexec # chroot /usr/sandbox -
The Linux Command Line
The Linux Command Line Fifth Internet Edition William Shotts A LinuxCommand.org Book Copyright ©2008-2019, William E. Shotts, Jr. This work is licensed under the Creative Commons Attribution-Noncommercial-No De- rivative Works 3.0 United States License. To view a copy of this license, visit the link above or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042. A version of this book is also available in printed form, published by No Starch Press. Copies may be purchased wherever fine books are sold. No Starch Press also offers elec- tronic formats for popular e-readers. They can be reached at: https://www.nostarch.com. Linux® is the registered trademark of Linus Torvalds. All other trademarks belong to their respective owners. This book is part of the LinuxCommand.org project, a site for Linux education and advo- cacy devoted to helping users of legacy operating systems migrate into the future. You may contact the LinuxCommand.org project at http://linuxcommand.org. Release History Version Date Description 19.01A January 28, 2019 Fifth Internet Edition (Corrected TOC) 19.01 January 17, 2019 Fifth Internet Edition. 17.10 October 19, 2017 Fourth Internet Edition. 16.07 July 28, 2016 Third Internet Edition. 13.07 July 6, 2013 Second Internet Edition. 09.12 December 14, 2009 First Internet Edition. Table of Contents Introduction....................................................................................................xvi Why Use the Command Line?......................................................................................xvi -
SUSE Linux Enterprise Server 12 Does Not Provide the Repair System Anymore
General System Troubleshooting Sascha Wehnert Premium Service Engineer Attachmate Group Germany GmbH [email protected] What is this about? • This session will cover the following topics: ‒ How to speed up a service request ‒ How to gather system information using supportconfig ‒ Configure serial console in grub to trace kernel boot messages ‒ Accessing a non booting systems using the rescue system ‒ System crash situations and how to prepare (i586/x86_64 only) 2 The challenge of a service request • Complete service request description: “We need to increase our disk space.” 3 The challenge of a service request • Which SUSE® Linux Enterprise Server version? • Is this a physical or virtual environment? • If virtual, what virtualization solution is being used? • If physical, local SCSI RAID array? What hardware? • If using HBAs, dm-multipathing or iSCSI connected disks or a 3rd party solution? • Disk and system partition layout? • What has been done so far? What was achieved? What failed? • What information do I need in order to help? 4 What information would be needed? • SUSE Linux Enterprise Server version → /etc/SuSE-release, uname -a • Physical → dmidecode XEN → /proc/xen/xsd_port KVM → /proc/modules • Hardware information → hwinfo • Partition information → parted -l, /etc/fstab • Multipathing/iSCSI → multipath, iscsiadm • Console output or /var/log/YaST2/y2log in case YaST2 has been used 5 supportconfig • Since SUSE Linux Enterprise Server 10 SP4 included in default installation. • Maintained package, updates available via patch channels. For best results always have latest version installed from channels installed. • One single command to get (almost) everything. • Splits data into files separated by topic. • Can be modified to exclude certain data, either via /etc/supportconfig.conf or command options. -
Scripting in Axis Network Cameras and Video Servers
Scripting in Axis Network Cameras and Video Servers Table of Contents 1 INTRODUCTION .............................................................................................................5 2 EMBEDDED SCRIPTS ....................................................................................................6 2.1 PHP .....................................................................................................................................6 2.2 SHELL ..................................................................................................................................7 3 USING SCRIPTS IN AXIS CAMERA/VIDEO PRODUCTS ......................................8 3.1 UPLOADING SCRIPTS TO THE CAMERA/VIDEO SERVER:...................................................8 3.2 RUNNING SCRIPTS WITH THE TASK SCHEDULER...............................................................8 3.2.1 Syntax for /etc/task.list.....................................................................................................9 3.3 RUNNING SCRIPTS VIA A WEB SERVER..............................................................................11 3.3.1 To enable Telnet support ...............................................................................................12 3.4 INCLUDED HELPER APPLICATIONS ..................................................................................13 3.4.1 The image buffer - bufferd........................................................................................13 3.4.2 sftpclient.........................................................................................................................16 -
Guidance on Sftp Chroot Access
Guidance On Sftp Chroot Access How comedic is Husein when tuberculose and untumbled Horace tango some bedstraw? Fucoid Sutherland revenge troubledly and alow, she regives her canvassing unfree unrecognisable. Sayer remains owlish: she phlebotomises her slaister distaste too glowingly? The server performs a chroot2 command to visit home loss of the ftp user. 13 2006 World Meteorological Organization WMO Guide to use of FTP and. Using sftp 199 Setting Permissions for File Uploads 200 244. CVE-2021-1145 A vulnerability in house Secure FTP SFTP of Cisco StarOS for Cisco. Match group yourgroupname ChrootDirectory home X11Forwarding no. Chroot A Linux command used to trace the root before It so often used for sandboxing. The Debian Administrator's Handbook. Selinux context to access on using ecr is to execute permissions of this is. Be replaced by sftp if possible ftp sftp access should be chrooted to. Both rsh and ssh require some coordination between the client and server. If you guidance on sftp chroot access is guidance on ams managed microsoft azure to chroot enforcements on. Are we in a chrooted jail and cannot access the hum system directly. Uses a Linux concept began as CHROOT to physically isolate each SFTP user to a violent part error the filesystem Thus art is lawn for an SFTP user to book another user's data. The file systems serving malware or are required so multiple queues and sftp on volatile data corruption, as having a long as efficiently run a long. The CA Access Control documentation uses the following file location. Guide following the Secure Configuration of another Hat Enterprise Linux. -
April 2006 Volume 31 Number 2
APRIL 2006 VOLUME 31 NUMBER 2 THE USENIX MAGAZINE OPINION Musings RIK FARROW OpenSolaris:The Model TOM HAYNES PROGRAMMING Code Testing and Its Role in Teaching BRIAN KERNIGHAN Modular System Programming in MINIX 3 JORRIT N. HERDER, HERBERT BOS, BEN GRAS, PHILIP HOMBURG, AND ANDREW S. TANENBAUM Some Types of Memory Are More Equal Than Others DIOMEDIS SPINELLIS Simple Software Flow Analysis Using GNU Cflow CHAOS GOLUBITSKY Why You Should Use Ruby LU KE KANIES SYSADMIN Unwanted HTTP:Who Has the Time? DAVI D MALONE Auditing Superuser Usage RANDOLPH LANGLEY C OLUMNS Practical Perl Tools:Programming, Ho Hum DAVID BLANK-EDELMAN VoIP Watch HEISON CHAK /dev/random ROBERT G. FERRELL STANDARDS USENIX Standards Activities NICHOLAS M. STOUGHTON B O OK REVIEWS Book Reviews ELIZABETH ZWICKY, WITH SAM STOVER AND RI K FARROW USENIX NOTES Letter to the Editor TED DOLOTTA Fund to Establish the John Lions Chair C ONFERENCES LISA ’05:The 19th Large Installation System Administration Conference WORLDS ’05: Second Workshop on Real, Large Distributed Systems FAST ’05: 4th USENIX Conference on File and Storage Technologies The Advanced Computing Systems Association Upcoming Events 3RD SYMPOSIUM ON NETWORKED SYSTEMS 2ND STEPS TO REDUCING UNWANTED TRAFFIC ON DESIGN AND IMPLEMENTATION (NSDI ’06) THE INTERNET WORKSHOP (SRUTI ’06) Sponsored by USENIX, in cooperation with ACM SIGCOMM JULY 6–7, 2006, SAN JOSE, CA, USA and ACM SIGOPS http://www.usenix.org/sruti06 MAY 8–10, 2006, SAN JOSE, CA, USA Paper submissions due: April 20, 2006 http://www.usenix.org/nsdi06 2006 -
The Linux Command Line
The Linux Command Line Second Internet Edition William E. Shotts, Jr. A LinuxCommand.org Book Copyright ©2008-2013, William E. Shotts, Jr. This work is licensed under the Creative Commons Attribution-Noncommercial-No De- rivative Works 3.0 United States License. To view a copy of this license, visit the link above or send a letter to Creative Commons, 171 Second Street, Suite 300, San Fran- cisco, California, 94105, USA. Linux® is the registered trademark of Linus Torvalds. All other trademarks belong to their respective owners. This book is part of the LinuxCommand.org project, a site for Linux education and advo- cacy devoted to helping users of legacy operating systems migrate into the future. You may contact the LinuxCommand.org project at http://linuxcommand.org. This book is also available in printed form, published by No Starch Press and may be purchased wherever fine books are sold. No Starch Press also offers this book in elec- tronic formats for most popular e-readers: http://nostarch.com/tlcl.htm Release History Version Date Description 13.07 July 6, 2013 Second Internet Edition. 09.12 December 14, 2009 First Internet Edition. 09.11 November 19, 2009 Fourth draft with almost all reviewer feedback incorporated and edited through chapter 37. 09.10 October 3, 2009 Third draft with revised table formatting, partial application of reviewers feedback and edited through chapter 18. 09.08 August 12, 2009 Second draft incorporating the first editing pass. 09.07 July 18, 2009 Completed first draft. Table of Contents Introduction....................................................................................................xvi -
In PDF Format
Arranging Your Virtual Network on FreeBSD Michael Gmelin ([email protected]) January 2020 1 CONTENTS CONTENTS Contents Introduction 3 Document Conventions . .3 License . .3 Plain Jails 4 Plain Jails Using Inherited IP Configuration . .4 Plain Jails Using a Dedicated IP Address . .5 Plain Jails Using a VLAN IP Address . .6 Plain Jails Using a Loopback IP Address . .7 Adding Outbound NAT for Public Traffic . .7 Running a Service and Redirecting Traffic to It . .9 VNET Jails and bhyve VMs 10 VNET Jails Using sysutils/pot ............................. 10 VNET Jails Using sysutils/iocage ............................ 13 Managing Bridges . 13 Adding bhyve VMs and DHCP to the Mix . 16 Preventing Traffic Between VNET Jails/VMs . 17 Firewalling Inside VNET Jails/VMs . 20 VXLAN 22 VXLAN Example Overview . 22 Gateway Configuration . 24 Jailhost-a . 25 Network Configuration (jailhost-a) . 25 VM Configuration (jailhost-a) . 26 Jail Configuration (jailhost-a) . 27 Jailhost-b . 27 Network Configuration (jailhost-b) . 27 Plain Jail Configuration (jailhost-b) . 28 Network Switch Setup (jailhost-b) . 29 VNET Jail Configuration (jailhost-b) . 30 VM Configuration (jailhost-b) . 30 VXLAN Multicast Troubleshooting . 31 Conclusion and Further Reading 33 2020-01-08 (final) 2 CC BY 4.0 INTRODUCTION Introduction Modern FreeBSD offers a range of virtualization options, from the traditional jail environment sharing the network stack with the host operating system, over vnet jails, which allow each jail to have its own network stack, to bhyve virtual machines running their own kernels/operating systems. Depending on individual requirements, there are different ways to configure the virtual network. Jail and VM management tools can ease the process by abstracting away (at least some of) the underlying complexities. -
What Is It We Want in Containers Anyways?
WHAT IS IT WE WANT IN CONTAINERS ANYWAYS? Vincent Batts @vbatts bit.ly/vbatts-containers-anyways bit.ly/252kBnL $> finger $(whoami) Login: vbatts Name: Vincent Batts Directory: /home/vbatts Shell: /bin/bash Such mail. Plan: OHMAN $> id -Gn devel opencontainers docker appc redhat golang slackware SO, WHY, CONTAINERS? Single Application Full System But Not a VM Except Maybe a VM Pods of applications Labels of services Non-root Desktop Applications OMG AND CATS https://www.flickr.com/photos/27549668@N03/ But wait, What does "container" mean to you? But wait, What does "container" mean to you? USE-CASE Reproducibility USE-CASE Ephemeral Environments USE-CASE Freedom from host restrictions USE-CASE Easy delivery USE-CASE Integrate to existing process USE-CASE Controls and knobs BUILD Dockerfile Source to Image (github.com/OpenShift/source-to-image) appc/acbuild (github.com/appc/acbuild) Your own Makefiles? SHARING registry (i.e. docker-registry, dockyard) Host it yourself (i.e. tarballs on an http server) Share recipes! TOOLS LXC / LXD lmctfy Docker systemd-nspawn runC bubblewrap TECH Namespaces Resource Controls Security and Isolation SYSTEMD systemd directives Security Slides (CoreOS Fest2016) SHELL unshare(1) mount(8) shared subtrees chroot(1) procfs, sysfs, tmpfs cgroup filesystem (not for the faint of heart) STANDARDS! Standard /ˈstandəd/ noun something used as a measure, norm, or model in comparative evaluations STANDARDS! Areas to Standardize: Packaging Runtime Networking Cloud Call to Action! Define your use-cases first Get involved in the conversations Ensure your container integration touchpoint stay generic, to avoid lock-in to a particular platform. PoC tooling for your integration VINCENT BATTS @VBATTS| [email protected] THANKS!.