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Heap Spraying
In computer security, heap spraying is a technique used in exploits to facilitate arbitrary code execution. The part of the source code of an exploit that implements this technique is called a heap spray. In general, code that ''sprays the heap'' attempts to put a certain sequence of bytes at a predetermined location in the memory of a target process by having it allocate (large) blocks on the process's heap and fill the bytes in these blocks with the right values. Operation A heap spray does not actually exploit any security issues but it can be used to make a vulnerability easier to exploit. A heap spray by itself cannot be used to break any security boundaries: a separate security issue is needed. Exploiting security issues is often hard because various factors can influence this process. Chance alignments of memory and timing introduce a lot of randomness (from the attacker's point of view). A heap spray can be used to introduce a large amount of order to compensate for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Security
Computer security (also cybersecurity, digital security, or information technology (IT) security) is a subdiscipline within the field of information security. It consists of the protection of computer software, systems and computer network, networks from Threat (security), threats that can lead to unauthorized information disclosure, theft or damage to computer hardware, hardware, software, or Data (computing), data, as well as from the disruption or misdirection of the Service (economics), services they provide. The significance of the field stems from the expanded reliance on computer systems, the Internet, and wireless network standards. Its importance is further amplified by the growth of smart devices, including smartphones, televisions, and the various devices that constitute the Internet of things (IoT). Cybersecurity has emerged as one of the most significant new challenges facing the contemporary world, due to both the complexity of information systems and the societi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
String (computer Science)
In computer programming, a string is traditionally a sequence of character (computing), characters, either as a literal (computer programming), literal constant or as some kind of Variable (computer science), variable. The latter may allow its elements to be Immutable object, mutated and the length changed, or it may be fixed (after creation). A string is often implemented as an array data structure of bytes (or word (computer architecture), words) that stores a sequence of elements, typically characters, using some character encoding. More general, ''string'' may also denote a sequence (or List (abstract data type), list) of data other than just characters. Depending on the programming language and precise data type used, a variable (programming), variable declared to be a string may either cause storage in memory to be statically allocated for a predetermined maximum length or employ dynamic allocation to allow it to hold a variable number of elements. When a string appears lit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Web Worker
A web worker, as defined by the World Wide Web Consortium (W3C) and the Web Hypertext Application Technology Working Group (WHATWG), is a JavaScript script executed from an HTML page that runs in the background, independently of scripts that may also have been executed from the same HTML page. Web workers are often able to utilize multi-core CPUs more effectively. The W3C and WHATWG envision web workers as long-running scripts that are not interrupted by scripts that respond to clicks or other user interactions. Keeping such workers from being interrupted by user activities should allow Web pages to remain responsive at the same time as they are running long tasks in the background. The web worker specification is part of the HTML Living Standard. Overview As envisioned by WHATWG, web workers are relatively heavy-weight and are not intended to be used in large numbers. They are expected to be long-lived, with a high start-up performance cost, and a high per-instance memory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canvas Element
The HTML canvas element allows for dynamic, scriptable rendering of 2D shapes and bitmap images. Introduced in HTML5, it is a low level, procedural model that updates a bitmap. The element also helps in making 2D games. While the element offers its own 2D drawing API, it also supports the WebGL API to allow 3D rendering with OpenGL ES. History Canvas was initially introduced by Apple for use in their own Mac OS X WebKit component in 2004, powering applications like Dashboard widgets and the Safari browser. Later, in 2005, it was adopted in version 1.8 of Gecko browsers, and Opera in 2006, and standardized by the Web Hypertext Application Technology Working Group (WHATWG) on new proposed specifications for next generation web technologies. Usage A canvas consists of a drawable region defined in HTML code with ''height'' and ''width'' attributes. JavaScript code may access the area through a full set of drawing functions similar to those of other common 2D APIs, thus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTML5
HTML5 (Hypertext Markup Language 5) is a markup language used for structuring and presenting hypertext documents on the World Wide Web. It was the fifth and final major HTML version that is now a retired World Wide Web Consortium (W3C) recommendation. The current specification is known as the HTML Living Standard. It is maintained by the Web Hypertext Application Technology Working Group (WHATWG), a consortium of the major browser vendors (Apple Inc., Apple, Google, Mozilla, and Microsoft). HTML5 was first released in a public-facing form on 22 January 2008, with a major update and "W3C Recommendation" status in October 2014. Its goals were to improve the language with support for the latest multimedia and other new features; to keep the language both easily readable by humans and consistently understood by computers and devices such as web browsers, Parsing, parsers, etc., without XHTML, XHTML's rigidity; and to remain backward-compatible with older software. HTML5 is intended t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adobe Flash
Adobe Flash (formerly Macromedia Flash and FutureSplash) is a mostly discontinuedAlthough it is discontinued by Adobe Inc., for the Chinese market it is developed by Zhongcheng and for the international enterprise market it is developed by Harman International. multimedia software platform used for production of animations, rich internet applications, desktop applications, mobile apps, mobile games, and embedded web browser video players. About Flash displays text, vector graphics, and raster graphics to provide animations, video games, and applications. It allows streaming of audio and video, and can capture mouse, keyboard, microphone, and camera input. Artists may produce Flash graphics and animations using Adobe Animate (formerly known as Adobe Flash Professional). Software developers may produce applications and video games using Adobe Flash Builder, FlashDevelop, Flash Catalyst, or any text editor combined with the Apache Flex SDK. End users view Flash co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ActionScript
ActionScript is an object-oriented programming language originally developed by Macromedia Inc. (later acquired by Adobe). It is influenced by HyperTalk, the scripting language for HyperCard. It is now an implementation of ECMAScript (meaning it is a superset of the syntax and semantics of the language more widely known as JavaScript), though it originally arose as a sibling, both being influenced by HyperTalk. ActionScript code is usually converted to bytecode format by a compiler. ActionScript is used primarily for the development of websites and software targeting the Adobe Flash platform, originally finding use on web pages in the form of embedded SWF files. ActionScript 3 is also used with the Adobe AIR system for the development of desktop and mobile applications. The language itself is open-source in that its specification is offered free of charge and both an open-source compiler (as part of Apache Flex) and open-source virtual machine ( Tamarin) are availabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VBScript
VBScript (Microsoft Visual Basic Scripting Edition) is a deprecated programming language for scripting on Microsoft Windows using Component Object Model (COM), based on classic Visual Basic and Active Scripting. It was popular with system administrators for managing computers and automating many aspects of computing environments, and has been installed by default in every desktop release of Microsoft Windows since Windows 98; in Windows Server since Windows NT 4.0 Option Pack; and optionally with Windows CE (depending on the device it is installed on). VBScript running environments include: Windows Script Host (WSH), Internet Explorer (IE), and Internet Information Services (IIS). The running environment is embeddable in other programs via the Microsoft Script Control (). In October 2023, Microsoft announced that VBScript was deprecated. In May 2024, a multi-phase deprecation schedule was announced with disabling it by default "around 2027" and removing it sometime later. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shellcode
In hacking, a shellcode is a small piece of code used as the payload in the exploitation of a software vulnerability. It is called "shellcode" because it typically starts a command shell from which the attacker can control the compromised machine, but any piece of code that performs a similar task can be called shellcode. Because the function of a payload is not limited to merely spawning a shell, some have suggested that the name shellcode is insufficient. However, attempts at replacing the term have not gained wide acceptance. Shellcode is commonly written in machine code. When creating shellcode, it is generally desirable to make it both small and executable, which allows it to be used in as wide a variety of situations as possible. In assembly code, the same function can be performed in a multitude of ways and there is some variety in the lengths of opcodes that can be used for this purpose; good shellcode writers can put these small opcodes to use to create more compact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicode
Unicode or ''The Unicode Standard'' or TUS is a character encoding standard maintained by the Unicode Consortium designed to support the use of text in all of the world's writing systems that can be digitized. Version 16.0 defines 154,998 Character (computing), characters and 168 script (Unicode), scripts used in various ordinary, literary, academic, and technical contexts. Unicode has largely supplanted the previous environment of a myriad of incompatible character sets used within different locales and on different computer architectures. The entire repertoire of these sets, plus many additional characters, were merged into the single Unicode set. Unicode is used to encode the vast majority of text on the Internet, including most web pages, and relevant Unicode support has become a common consideration in contemporary software development. Unicode is ultimately capable of encoding more than 1.1 million characters. The Unicode character repertoire is synchronized with Univers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control characters a total of 128 code points. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers; for example, the first 128 code points of Unicode are the same as ASCII. ASCII encodes each code-point as a value from 0 to 127 storable as a seven-bit integer. Ninety-five code-points are printable, including digits ''0'' to ''9'', lowercase letters ''a'' to ''z'', uppercase letters ''A'' to ''Z'', and commonly used punctuation symbols. For example, the letter is represented as 105 (decimal). Also, ASCII specifies 33 non-printing control codes which originated with ; most of which are now obsolete. The control cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
