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In computing, BIOS is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process. The firmware comes pre-installed on the computer's motherboard.
The Pentium FDIV bug is a hardware bug affecting the floating-point unit (FPU) of the early Intel Pentium processors. Because of the bug, the processor would return incorrect binary floating point results when dividing certain pairs of high-precision numbers. The bug was discovered in 1994 by Thomas R. Nicely, a professor of mathematics at Lynchburg College. Missing values in a lookup table used by the FPU's floating-point division algorithm led to calculations acquiring small errors. While these errors would in most use-cases only occur rarely and result in small deviations from the correct output values, in certain circumstances the errors can occur frequently and lead to more significant deviations.
A software bug is a bug in computer software.
An undocumented feature is an unintended or undocumented hardware operation, for example an undocumented instruction, or software feature found in computer hardware and software that is considered beneficial or useful. Sometimes the documentation is omitted through oversight, but undocumented features are sometimes not intended for use by end users, but left available for use by the vendor for software support and development. Also, some unintended operation of hardware or software that ends up being of utility to users is simply a bug, flaw or quirk.
In computer engineering, Halt and Catch Fire, known by the assembly language mnemonic HCF, is an idiom referring to a computer machine code instruction that causes the computer's central processing unit (CPU) to cease meaningful operation, typically requiring a restart of the computer. It originally referred to a fictitious instruction in IBM System/360 computers, making a joke about its numerous non-obvious instruction mnemonics.
System Management Mode is an operating mode of x86 central processor units (CPUs) in which all normal execution, including the operating system, is suspended. An alternate software system which usually resides in the computer's firmware, or a hardware-assisted debugger, is then executed with high privileges.
Intel Trusted Execution Technology is a computer hardware technology of which the primary goals are:
An illegal opcode, also called an unimplemented operation, unintended opcode or undocumented instruction, is an instruction to a CPU that is not mentioned in any official documentation released by the CPU's designer or manufacturer, which nevertheless has an effect. Illegal opcodes were common on older CPUs designed during the 1970s, such as the MOS Technology 6502, Intel 8086, and the Zilog Z80. On these older processors, many exist as a side effect of the wiring of transistors in the CPU, and usually combine functions of the CPU that were not intended to be combined. On old and modern processors, there are also instructions intentionally included in the processor by the manufacturer, but that are not documented in any official specification.
Intel vPro technology is an umbrella marketing term used by Intel for a large collection of computer hardware technologies, including VT-x, VT-d, Trusted Execution Technology (TXT), and Intel Active Management Technology (AMT). When the vPro brand was launched, it was identified primarily with AMT, thus some journalists still consider AMT to be the essence of vPro.
Sandy Bridge is the codename for Intel's 32 nm microarchitecture used in the second generation of the Intel Core processors. The Sandy Bridge microarchitecture is the successor to Nehalem and Westmere microarchitecture. Intel demonstrated an A1 stepping Sandy Bridge processor in 2009 during Intel Developer Forum (IDF), and released first products based on the architecture in January 2011 under the Core brand.
Intel Active Management Technology (AMT) is hardware and firmware for remote out-of-band management of select business computers, running on the Intel Management Engine, a microprocessor subsystem not exposed to the user, intended for monitoring, maintenance, updating, and repairing systems. Out-of-band (OOB) or hardware-based management is different from software-based management and software management agents.
Transactional Synchronization Extensions (TSX), also called Transactional Synchronization Extensions New Instructions (TSX-NI), is an extension to the x86 instruction set architecture (ISA) that adds hardware transactional memory support, speeding up execution of multi-threaded software through lock elision. According to different benchmarks, TSX/TSX-NI can provide around 40% faster applications execution in specific workloads, and 4–5 times more database transactions per second (TPS).
The Intel Management Engine (ME), also known as the Intel Manageability Engine, is an autonomous subsystem that has been incorporated in virtually all of Intel's processor chipsets since 2008. It is located in the Platform Controller Hub of modern Intel motherboards.
Meltdown is one of the two original transient execution CPU vulnerabilities. Meltdown affects Intel x86 microprocessors, IBM Power microprocessors, and some ARM-based microprocessors. It allows a rogue process to read all memory, even when it is not authorized to do so.
Spectre is one of the two original transient execution CPU vulnerabilities, which involve microarchitectural side-channel attacks. These affect modern microprocessors that perform branch prediction and other forms of speculation. On most processors, the speculative execution resulting from a branch misprediction may leave observable side effects that may reveal private data to attackers. For example, if the pattern of memory accesses performed by such speculative execution depends on private data, the resulting state of the data cache constitutes a side channel through which an attacker may be able to extract information about the private data using a timing attack.
Lazy FPU state leak, also referred to as Lazy FP State Restore or LazyFP, is a security vulnerability affecting Intel Core CPUs. The vulnerability is caused by a combination of flaws in the speculative execution technology present within the affected CPUs and how certain operating systems handle context switching on the floating point unit (FPU). By exploiting this vulnerability, a local process can leak the content of the FPU registers that belong to another process. This vulnerability is related to the Spectre and Meltdown vulnerabilities that were publicly disclosed in January 2018.
Foreshadow, known as L1 Terminal Fault (L1TF) by Intel, is a vulnerability that affects modern microprocessors that was first discovered by two independent teams of researchers in January 2018, but was first disclosed to the public on 14 August 2018. The vulnerability is a speculative execution attack on Intel processors that may result in the disclosure of sensitive information stored in personal computers and third-party clouds. There are two versions: the first version (original/Foreshadow) targets data from SGX enclaves; and the second version (next-generation/Foreshadow-NG) targets virtual machines (VMs), hypervisors (VMM), operating systems (OS) kernel memory, and System Management Mode (SMM) memory. A listing of affected Intel hardware has been posted.
In digital computing, hardware security bugs are hardware bugs or flaws that create vulnerabilities affecting computer central processing units (CPUs), or other devices which incorporate programmable processors or logic and have direct memory access, which allow data to be read by a rogue process when such reading is not authorized. Such vulnerabilities are considered "catastrophic" by security analysts.
The Microarchitectural Data Sampling (MDS) vulnerabilities are a set of weaknesses in Intel x86 microprocessors that use hyper-threading, and leak data across protection boundaries that are architecturally supposed to be secure. The attacks exploiting the vulnerabilities have been labeled Fallout, RIDL, ZombieLoad., and ZombieLoad 2.
Transient execution CPU vulnerabilities are vulnerabilities in a computer system in which a speculative execution optimization implemented in a microprocessor is exploited to leak secret data to an unauthorized party. The archetype is Spectre, and transient execution attacks like Spectre belong to the cache-attack category, one of several categories of side-channel attacks. Since January 2018 many different cache-attack vulnerabilities have been identified.
References
- ↑ Nicholas Carr. "'IT'S NOT A BUG, IT'S A FEATURE.' TRITE—OR JUST RIGHT?". Wired.
- ↑ Lucian Armasu (29 March 2019). "Intel Chipsets' Undocumented Feature Can Help Hackers Steal Data". Tom's Hardware.