Which Linux or UNIX Version Am I Running? For system administrators maintaining patch levels and an accurate.Unix security - Wikipedia, the free encyclopedia. Unix security refers to the means of securing a Unix or Unix- likeoperating system. A secure environment is achieved not only by the design concepts of these operating systems, but also through vigilant user and administrative practices. Design concepts. All files in a typical Unix- style filesystem have permissions set enabling different access to a file. Planning for client deployment to Linux and UNIX computers in System Center Configuration Manager. Required operating system patch: PAM memory. Version of the operating system: AIX 5.3, Technology Level 6, Service. The following Linux and UNIX operating systems that are supported as clients for. Linux / Unix Command: patch. You can save people a lot of grief by keeping a patchlevel.h file which is patched to increment the patch level as the. Permissions on a file are commonly set using the chmod command and seen through the ls command. For example. - r- xr- xr- x 1 root wheel 7. Sep 8 2. 00. 2 /bin/sh. Unix permissions permit different users access to a file. Different user groups have different permissions on a file. Tru64 UNIX operating system. Tru64 UNIX and TruCluster Patch Kit Map V5.1B* V5.1A. I am a new Linux and Unix system user. I also know that I can patch binary package using up2date or yum command in Linux. I was wondering is if there’s a way to apply a patch file to downloaded source code on a Linux / UNIX. A patch is a piece of software designed to update a computer program or its supporting data, to fix or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually called bugfixes or bug. System Requirements -- Unix-based Operating System Module Version 3.5. Shell-level access to each target system using a standard user account. More advanced Unix filesystems include the Access Control List concept which allows permissions to be granted to multiple users or groups. An Access Control List may be used to grant permission to additional individual users or groups. This enables users to be grouped by the level of access they have to this system. Many Unix implementations add an additional layer of security by requiring that a user be a member of the wheeluser privileges group in order to access the su command. If access to this account is gained by an unwanted user, this results in a complete breach of the system. A root account however is necessary for administrative purposes, and for the above security reasons the root account is seldom used for day to day purposes (the sudo program is more commonly used), so usage of the root account can be more closely monitored. Root access . Clark Kent becomes Superman for only as long as necessary, in order to save people. He then reverts to his . Root access should be used in the same fashion. The Clark Kent disguise doesn't really restrict him though, as he is still able to use his super powers. This is analogous to using the sudo program. User and administrative techniques. In Unix systems, the essential information about users is stored under the file /etc/passwd. Refer to your UNIX operating system Administrator's Guide or contact. This file keeps track of the users registered in the system and their main definitions. Passwords, or more correctly, the hash of the password, can also be stored in the same place. The entries in /etc/passwd occupy exactly one line each, and have the following form. Saraiva: /home/xfze: /bin/bash. Since all users must have read access to the /etc/passwd file to do many common tasks (ls - l /home will use /etc/passwd to map UIDs to login names for example), anyone could also read the password hashes of other users. To solve this problem, the file /etc/shadow was created to store the password hashes, with only root having read access. Under password shadowing, the 2nd field (password hash) is replaced by an 'x' which tells the system to retrieve the corresponding user's password via the /etc/shadow file. The /etc/shadow file often only contains values for the first two fields. W2n. X3sslp. 3q. Jm. MYDdgl. EAp. Ac. 36r/: :: :. The remaining fields in the /etc/shadow file include: The minimum number of days between password changes. The maximum number of days until the password must be changed. The number of days of warning given before the password must be changed. The number of days after the password must be changed when the account becomes unusable. The date (expressed as the number of days since January 1st, 1. These fields may be used to improve Unix security by enforcing a password security policy. Users and accounts. Patching the operating system in a secure manner requires that the software come from a trustworthy source and not have been altered since it was packaged. Common methods for verifying that operating system patches have not been altered include the use of cryptographic hash, such as an MD5 based checksum, or the use of read- only media. From a security standpoint, the specific packaging method, such as the RPM Package Manager format originally from Red Hat Linux is not as important as the use of features which ensure the integrity of the patch itself. Source distributions. The drawback, absent an accompanying cryptographic hash value, is that the user must be able to perform a security analysis of the code themselves. RPM packages. The hash values are packaged with the RPM file and verified when the package is installed. Debian packages. A signature is computed when the package is constructed and verified later when the package is installed. Other vendors and distributions. Software which is no longer required should be removed completely, if possible. Identify what services are running. Free. BSD)The commands inetd and xinetd act as super- servers for a variety of network protocols such as rlogin, telnet and ftp. Turning off unnecessary servicesusing update- rc. Debianusing chkconfig on Red Hat Linuxusing /etc/rc. Free. BSD (mention /etc/rc. Gentoo Linux. This approach is usually called proactive security. There are some operating systems which are secure by default. Amongst others, the free BSD flavours (Free. BSD, Net. BSD, and Open. BSD) are proactively secure. For example, the output of netstat on a Net. BSD 3. 0 workstation clearly outlines this technique: $ netstat - a. Active Internet connections (including servers)Proto Recv- Q Send- Q Local Address Foreign Address Statetcp 0 0 localhost. LISTENtcp 0 0 *. LISTENActive Internet. Proto Recv- Q Send- Q Local Address Foreign Address (state)tcp. LISTENtcp. 6 0 0 *. LISTENActive UNIX domain sockets. Address Type Recv- Q Send- Q Inode Conn Refs Nextref Addrc. The following example from a BSD system$ sockstat - 4. USER COMMAND PID FD PROTO LOCAL ADDRESS FOREIGN ADDRESSroot sendmail 5. Shows that on this machine only the SSH service is listening to the public network interface of the computer. Access to a service may be further restricted by using a firewall. File systems. These permissions apply almost equally to all filesystem objects such as files, directories and devices. The 9 permission bits are divided into three groups of three bits each. The first group describes the permissions of the file owner, the second group describes the permissions of a group associated with the file owner or the directory containing the file, and the third group describes the permissions associated with any process which does not have the same user ID as the file. Each group of three bits contains a bit indicating the read, write or execute access is granted. In the case of directories, execute access is interpreted as the permission to perform a filename lookup within the directory. The set user ID and set group ID bits, commonly abbreviated set- UID and set- GID respectively, are used to change the identity of the process which executes a file having either or both of those bits set. A file having the set- UID permission bit set will cause a process which executes that file to temporarily switch the effective user ID to that of the file owner. A file having the set- GID permission bit set will cause a process which executes that file to temporarily switch the effective group ID to that of the file group. A process may then alternate between the effective user or group ID which it inherited from the file and the real user or group ID which it inherited when the user logged on to the system. This provides a mechanism by which a process may limit the access rights it possesses to those code regions which require those access rights. This is a form of a security technique known as privilege separation and improves program security by limiting the unintended or undesirable actions of a processes. A directory having the set- GID permission bit set will cause a newly created file to have an initial file group value equal to the file group of the directory. This provides a mechanism whereby a subsystem, such as the system's mail subsystem, can create files which have a common file group value so that set- GID processes within that subsystem are then able to read or write the file. The sticky bit, formally known as the save text on swap bit, derives its name from its original purpose. Originally the sticky bit caused a process's initial memory image to be stored as a contiguous image on the disk drive which was used to store real memory pages when they were not in use. This improved the performance of commonly executed commands by making the initial memory image readily available. Modern UNIX systems no longer perform that function when the bit is set, but the name has been preserved nonetheless. In the case of files, the sticky- bit may be used by the system to indicate the style of file locking to be performed. In the case of directories, the sticky bit prevents any process, other than one which has super- user privileges or one having an effective user ID of the file owner, from deleting a file within that directory. The sticky bit is most commonly used on publicly writable directories, such as the various temporary working space directories on the system. Root squash. It is primarily a feature of NFS but may be available on other systems as well. This problem arises when a remote file system is shared by multiple users. These users belong to one or multiple groups. In Unix, every file and folder normally has separate permissions (read, write, execute) for the owner (normally the creator of the file), for the group to which the owner belongs, and for the . This allows restriction of read and write access only to the authorized users while in general the NFS server must also be protected by firewall. A superuser has more rights than an ordinary user, being able to change the file ownership, set arbitrary permissions, and access all protected content. Even users that do need to have root access to individual workstations may not be authorized for the similar actions on a shared file system. Root squash reduces rights of the remote root, making one no longer superuser. On UNIX like systems, root squash option can be turned on and off in /etc/exports file on a server side. Patch (computing) - Wikipedia, the free encyclopedia. Not to be confused with Hotfix. A patch is a piece of software designed to update a computer program or its supporting data, to fix or improve it. Although meant to fix problems, poorly designed patches can sometimes introduce new problems (see software regressions). In some special cases updates may knowingly break the functionality, for instance, by removing components for which the update provider is no longer licensed or disabling a device. Patch management is the process of using a strategy and plan of what patches should be applied to which systems at a specified time. Patches for proprietary software are typically distributed as executable files instead of source code. This type of patch modifies the program executable. In this case, the patches usually consist of textual differences between two source code files, called . These types of patches commonly come out of open- source projects. In these cases, developers expect users to compile the new or changed files themselves. Because the word . Bulky patches or patches that significantly change a program may circulate as . Microsoft Windows NT and its successors (including Windows 2. Windows XP, Windows Vista and Windows 7) use the . Note physical patches used to correct punched holes by covering them. Historically, software suppliers distributed patches on paper tape or on punched cards, expecting the recipient to cut out the indicated part of the original tape (or deck), and patch in (hence the name) the replacement segment. Later patch distributions used magnetic tape. Then, after the invention of removable disk drives, patches came from the software developer via a disk or, later, CD- ROM via mail. With the widely available Internet access, downloading patches from the developer's web site or through automated software updates became often available to the end- users. Starting with Apple's Mac OS 9 and Microsoft's Windows ME, PC operating systems gained the ability to get automatic software updates via the Internet. Computer programs can often coordinate patches to update a target program. Automation simplifies the end- user. Service packs for Microsoft Windows NT and its successors and for many commercial software products adopt such automated strategies. Some programs can update themselves via the Internet with very little or no intervention on the part of users. The maintenance of server software and of operating systems often takes place in this manner. In situations where system administrators control a number of computers, this sort of automation helps to maintain consistency. The application of security patches commonly occurs in this manner. Application. In particular, patches can become quite large when the changes add or replace non- program data, such as graphics and sounds files. Such situations commonly occur in the patching of computer games. Compared with the initial installation of software, patches usually do not take long to apply. In the case of operating systems and computer server software, patches have the particularly important role of fixing security holes. Some critical patches involve issues with drivers. To facilitate updates, operating systems often provide automatic or semi- automatic updating facilities. Completely automatic updates have not succeeded in gaining widespread popularity in corporate computing environments, partly because of the aforementioned glitches, but also because administrators fear that software companies may gain unlimited control over their computers. Cautious users, particularly system administrators, tend to put off applying patches until they can verify the stability of the fixes. Microsoft (W)SUS support this. In the cases of large patches or of significant changes, distributors often limit availability of patches to qualified developers as a beta test. Applying patches to firmware poses special challenges, as it often involves the provisioning of totally new firmware images, rather than applying only the differences from the previous version. The patch usually consists of a firmware image in form of binary data, together with a supplier- provided special program that replaces the previous version with the new version; a motherboard. BIOS update is an example of a common firmware patch. Any unexpected error or interruption during the update, such as a power outage, may render the motherboard unusable. It is possible for motherboard manufacturers to put safeguards in place to prevent serious damage; for example, the upgrade procedure could make and keep a backup of the firmware to use in case it determines that the primary copy is corrupt (usually through the use of a checksum, such as a CRC). Video games. These patches may be prompted by the discovery of exploits in the multiplayer game experience that can be used to gain unfair advantages over other players. Extra features and game play tweaks can often be added. These kinds of patches are common in first- person shooters with multiplayer capability, and in MMORPGs, which are typically very complex with large amounts of content, almost always rely heavily on patches following the initial release, where patches sometimes add new content and abilities available to players. Because the balance and fairness for all players of an MMORPG can be severely corrupted within a short amount of time by an exploit, servers of an MMORPG are sometimes taken down with short notice in order to apply a critical patch with a fix. In software development. This commonly occurs on very large- scale software projects, but rarely in small- scale development. In open- source projects, the authors commonly receive patches or many people publish patches that fix particular problems or add certain functionality, like support for local languages outside the project's locale. In an example from the early development of the Linux operating system (noted for publishing its complete source code), Linus Torvalds, the original author, received hundreds of thousands of patches from many programmers to apply against his original version. The Apache HTTP Server originally evolved as a number of patches that Brian Behlendorf collated to improve NCSA HTTPd, hence a name that implies that it is a collection of patches (. The FAQ on the project's official site states that the name 'Apache' was chosen from respect for the Native American Indian tribe of Apache. However, the 'a patchy server' explanation was initially given on the project's website. This corrective action will prevent successful exploitation and remove or mitigate a threat. Currently Microsoft releases its security patches once a month, and other operating systems and software projects have security teams dedicated to releasing the most reliable software patches as soon after a vulnerability announcement as possible. Security patches are closely tied to responsible disclosure. Unofficial patches. Similar to an ordinary patch, it alleviates bugs or shortcomings. Examples are security fixes by security specialists when an official patch by the software producers itself takes too long. This addresses problems related to unavailability of service provided by the system or the program. Retrieved 1. 4 October 2. Computercare's Laptop Repair Workbook: The 3. Cases of Classic Notebook Computers Troubleshooting and Repair. Uninstall High Definition Audio driver patch KB8. KB8. 88. 11. 1 . Another unofficial patch has been released to counter a critical flaw in Microsoft. Organized under the name Myth. Developers, this all- volunteer group of programmers, artists, and other talented people devote their time to improving and supporting further development of the Myth game series. Technology Innovation Management Review. The community was predictably upset. Instead of giving up on the game, users decided that if Activision wasn't going to fix the bugs, they would. They wanted to save the game by getting Activision to open the source so it could be kept alive beyond the point where Activision lost interest. With some help from members of the development team that were active on fan forums, they were eventually able to convince Activision to release Call to Power II's source code in October of 2.
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