PaX is a patch for the Linux kernel that implements least privilege protections for memory pages.

PaX offers executable space protection, using ( or emulating in operating system software ) the functionality of an NX bit ( i. e., built-in CPU / MMU support for memory contents execution privilege tagging ).

* March 4, 2005: VMA Mirroring vulnerability announced, new versions of PaX and grsecurity released, all prior versions utilizing SEGMEXEC and RANDEXEC have a privilege escalation vulnerability

* PaX privilege elevation proof-of-concept code 2005

* PaX, a Linux kernel security patch introduced in 2000

In addition to the LFS and BLFS books, Cross Linux from Scratch ( CLFS ) describes cross compiling and Hardened Linux From Scratch ( HLFS ) focuses on security enhancements like the use of Stack-smashing protection, PaX and Address space layout randomization using grsecurity.

PIE binaries are used in some security-focused Linux distributions to allow PaX or Exec Shield to use address space layout randomization to prevent attackers from knowing where existing executable code is during a security attack using exploits that rely on knowing the offset of the executable code in the binary, such as return-to-libc attacks.

There was a point in time when PaX had a configuration option to honor these settings ; that option has henceforth been intentionally removed for security reasons, as it was deemed not useful.

At the cost of a small amount of overhead, PaX reduces many security exploits to a denial of service ( DoS ) or a remote code-flow control ; exploits which would normally give attackers root access, allow access to important information on a hard drive, or cause other damage that will instead cause the affected program or process to crash with little effect on the rest of the system.

The PaX approach is thus not well suited to all circumstances ; however, in many cases, it is an acceptable method of protecting confidential information by preventing successful security breaches.

With mprotect () restrictions enabled, a program can no longer violate the non-executable pages policy that PaX initially sets down on all memory allocations ; thus, restricted mprotect () could be considered to be strict enforcement of the security policy, whereas the " Enforced non-executable pages " without these restrictions could be considered to be a looser form of enforcement.

The randomization of the executable load base for ET_EXEC fixed position executables was affected by a security flaw in the VM mirroring code in PaX.

The grsecurity project supplies several Linux kernel security enhancements, and supplies PaX along with those features unique to grsecurity.

Two years after ASLR was invented and published as part of PaX, a popular security patch for Linux, OpenBSD became the first mainstream operating system to support partial ASLR ( and to activate it by default ).

** grsecurity is a complete security solution providing such features as a MAC or RBAC system, chroot restrictions, address space modification protection ( via PaX ), auditing features, randomization features, linking restrictions to prevent file race conditions, ipc protections and much more.

PaX also cannot block some format string bug based attacks, which may allow arbitrary reading from and writing to data locations in memory using already existing code ; the attacker does not need to know any internal addresses or inject any code into a program to execute these types of attacks.

* April 1, 2005: Due to that vulnerability, the PaX project was scheduled to be taken over by a new developer, but since no candidate showed up, the old developer has continued maintenance ever since.

* STRIDE ( security ), denial of service, elevation of privilege, information disclosure, repudiation, spoofing, tampering

* Vertical privilege escalation, also known as privilege elevation, where a lower privilege user or application accesses functions or content reserved for higher privilege users or applications ( e. g. Internet Banking users can access site administrative functions or the password for smartphone can be bypassed.

Systrace is particularly useful when running untrusted or binary-only applications and provides facilities for privilege elevation on a system call basis, helping to eliminate the need for potentially dangerous setuid programs.

* Privilege elevation: Using Systrace's privilege elevation mode, it's possible to get rid of setuid binaries.

There exist several frontends to for use in a GUI environment, notably, and, and user interfaces not directly built on but providing similar temporary privilege elevation for administrative purposes, such as User Account Control in Microsoft Windows.

Other approaches need to be taken however, when you are dealing with injection of user code on the user machine, resulting in privilege elevation attacks.

On November 7, 2007 Microsoft stated that " there is vulnerability in Macrovision SECDRV. SYS driver on Windows and it could allow elevation of privilege.

Following the elevation of Cardinal Darío Castrillón Hoyos to the rank of Cardinal-Priest on 1 March 2008, Cacciavillan, as the longest serving Cardinal-Deacon ( in order of appointment to the College of Cardinals ), became Cardinal Protodeacon, whose special privilege it is to make the Habemus Papam announcement upon the conclusion of a papal conclave.

In the context of security the minimality principle of microkernels is a direct consequence of the principle of least privilege, according to which all code should have only the privileges needed to provide required functionality.

The state secrets privilege allows the president and the executive branch to withhold information or documents from discovery in legal proceedings if such release would harm national security.

Sendmail itself incorporated a certain amount of privilege separation in order to avoid exposure to security issues.

Project MAC at MIT, working with GE and BTL, developed Multics, which introduced the concept of ringed security privilege levels.

An underlying principle of SoD is that no individual should be able to effect a breach of security through dual privilege.

Trusted Xenix was a variant developed by Trusted Information Systems which incorporated the Bell-La Padula model of multilevel security, and had a multilevel secure interface for the STU-III secure communications device ( that is, an STU-III connection would only be made available to applications running at the same privilege level as the key loaded in the STU-III ).

In an otherwise seemingly thorough account, Cicero makes no mention of Bona Dea's May festival, and claims the goddess ' cult as an aristocratic privilege from the first ; the impeccably patrician Clodius, Cicero's social superior by birth, is presented as an innately impious, low-class oaf, and his popularist policies as threats to Rome's moral and religious security.

The design of the microprocessor architecture on practically all modern systems ( except some embedded systems ) involves a security model ( such as the rings model ) which specifies multiple privilege levels under which software may be executed ; for instance, a program is usually limited to its own address space so that it cannot access or modify other running programs or the operating system itself, and a program is usually prevented from directly manipulating hardware devices ( e. g. the frame buffer or network devices ).

The term " system administrator " may also be used to describe a security privilege which is assigned to a user or users of a specific computer, server, network or other IT System.

The most common technique leverages security vulnerabilities to achieve surreptitious privilege escalation.

Applying security patches, implementing the principle of least privilege, reducing the attack surface and installing antivirus software are some standard security best practices that are effective against all classes of malware.

* Principle of least privilege ( computer security )

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.

Chief Justice Burger further stated that executive privilege would most effectively apply when the oversight of the executive would impair that branch's national security concerns.

In it, he articulates a vision of progressive values based on four core lessons: 1 ) Progressives stand with people, not privilege ; 2 ) Progressives believe in the Common Good and a government that offers a hand up ; 3 ) Progressives hold that all people are equal in the eyes of God and under the law ; and 4 ) Progressives stand for universal human rights and cooperative global security.

* principle of least privilege, a security guideline

Capability-based security refers to the principle of designing user programs such that they directly share capabilities with each other according to the principle of least privilege, and to the operating system infrastructure necessary to make such transactions efficient and secure.

Due to national security concerns, other members of congress later revoked the privilege by the summer of 2003.

Since then, Nixon's successors have sometimes asserted that they may act in the interests of national security or that executive privilege shields them from Congressional oversight.

* Cross Zone Scripting is a type of privilege escalation attack in which a website subverts the security model of web browsers so that it can run malicious code on client computers.

The result is that the application performs actions with the same but different security context than intended by the application developer or system administrator ; this is effectively a limited form of privilege escalation ( specifically, the unauthorized assumption of the capability of impersonating other users ).