Training & Professional Development

unauthenticated scan

A form of vulnerability scan that tests the target systems without having passwords or other special information that would grant the scanner special privileges. This allows the scan to run from the perspective of an attacker but also limits the ability of the scanner to fully evaluate possible vulnerabilities.

unclassified

The lowest level of government/military classification. Used for data that is neither sensitive nor classified. Disclosure of unclassified data does not compromise confidentiality, and it doesn't cause any noticeable damage.

underflow

This error happens when the write buffer of the drive empties during the writing process, which causes an error on the media, rendering it useless.

unicast

A communications transmission to a single identified recipient.

unified threat management (UTM)

A security device that includes traditional functions of a firewall such as packet filtering and stateful inspection. It is able to perform packet inspection techniques, allowing it to identify and block malicious traffic. It can filter malware using definition files and/or whitelists and blacklists. It also includes intrusion- detection and/or intrusion-prevention capabilities. Aka next-generation firewall.

Uniform Computer Information Transactions Act (UCITA)

A federal law designed for adoption by each of the 50 states to provide a common framework for the conduct of computer-related business transactions.

uninterruptible power supply (UPS)

A type of self-charging battery that can be used to supply consistent clean power to sensitive equipment. A UPS functions by taking power in from the wall outlet, storing it in a battery, pulling power out of the battery, and thenA type of self-charging battery that can be used to supply consistent clean power to sensitive equipment. A UPS functions by taking power in from the wall outlet, storing it in a battery, pulling power out of the battery, and then feeding that power to whatever devices are connected to it. By directing current through its battery, it is able to maintain a consistent clean power supply.

unit testing

A method of testing software. Each unit of code is tested independently to discover any errors or omissions and to ensure that it functions properly. Unit testing should be performed by the development staff.

unshielded twisted-pair (UTP)

A twisted-pair wire that does not include additional EMI protection. Most twisted-pair wiring is UTP.

upper management

See senior management.

USA Patriot Act of 2001

An act implemented after the September 11, 2001, terrorist attacks. It greatly broadened the powers of law enforcement organizations and intelligence agencies across a number of areas, including the monitoring of electronic communications.

user

Any person who has access to the secured system. A user's access is tied to their work tasks and is limited so they have only enough access to perform the tasks necessary for their job position (in other words, principle of least privilege). Also referred to as an end user and employee.

User Datagram Protocol (UDP)

A connectionless protocol located at layer 4 of the OSI model.

user mode

The basic mode used by the CPU when executing user applications.

VENONA

One of the major intelligence successes of the United States resulted when cryptanalysts broke a top-secret Soviet cryptosystem, i.e., VENONA, that relied on the use of one-time pads.

Vernam cipher

A device that implements a 26-character modulo 26 substitution cipher. It functions as a one-time pad.

view

A client interface used to interact with a database. The view limits what clients can see and what functions they can perform.

Vigenere cipher

A polyalphabetic substitution cipher.

violation analysis

A form of auditing that uses clipping levels.

virtual machine

A software simulation of a computer within which a process executes. Each virtual machine has its own memory address space, and communication between virtual machines is securely controlled.

virtual memory

A special type of secondary memory that is managed by the operating system in such a manner that it appears to be real memory.

virtual private network (VPN)

A network connection established between two systems over an existing private or public network. A VPN provides confidentiality and integrity for network traffic through the use of encryption.

virtual private network (VPN) protocol

The protocols, such as PPTP, L2TP, and IPSec, that are used to create VPNs.

virtualization

A technology used to host one or more operating systems within the memory of a single host computer. This mechanism allows virtually any OS to operate on any hardware. It also allows multiple operating systems to work simultaneously on the same hardware.

virus

The oldest form of malicious code objects that plague cyberspace. Once they are in a system, they attach themselves to legitimate operating system and user files and applications and normally perform some sort of undesirable action, ranging from the somewhat innocuous display of an annoying message on the screen to the more malicious destruction of the entire local filesystem.

virus decryption routine

In an encrypted virus, a short segment of code that contains the cryptographic information necessary to load and decrypt the main virus code stored elsewhere on the disk.

virus hoax

See hoax.

vishing

A form of phishing that uses Voice over IP (VoIP) to trick users. It will often spoof the caller's actual phone number by fooling the caller ID system.

VLAN

A logical network segmentation implemented on switches and bridges to manage traffic. Multiple VLANs can be hosted on the same switch but are isolated as if they are separate physical networks. Only through a routing function, often provided by a multilayer switch, can cross-VLAN communications occur. VLANs function like physical network segments.

VLAN hopping

The ability to make network traffic jump between VLANs through an abuse of IEEE 802.1Q VLAN tagging known as double encapsulation.

Voice over IP (VoIP)

A network service that provides voice communication services by transporting the voice traffic as network packets over an IP network.

voice pattern

An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The speech, tone, modulation, and pitch patterns of a person's voice are used to establish identity or provide authentication.

volatile

See volatile storage.

volatile storage

A storage medium, such as RAM, that loses its contents when power is removed from the resource.

voluntary surrender

The act of willingly handing over evidence.

vulnerability

A weakness. It can be due to the existence of a flaw, loophole, oversight, error, limitation, frailty, or susceptibility in the IT infrastructure or any other aspect of an organization. It can also be the result of the absence of a safeguard or countermeasure or a weakness in a protection measure.

vulnerability analysis

A process used to identify vulnerabilities, or weaknesses. It can include both technical means, such as vulnerability scans, and nontechnical means, such as an evaluation or inspection of existing data on threats and vulnerabilities.

vulnerability management

A program used to detect weaknesses within an organization. Vulnerability scans and vulnerability assessments are two common elements of a vulnerability management program. Vulnerability scans are technical scans performed regularly, and vulnerability assessments are normally combined with a risk assessment.

vulnerability scan

A test performed on a system to find weaknesses in the security infrastructure. Vulnerability scans automatically probe systems, applications, and networks looking for weaknesses that may be exploited by an attacker. The scanning tools used in these tests provide quick point-and-click tests that perform otherwise tedious tasks without requiring manual intervention.

vulnerability scanner

A tool used to test a system for known security vulnerabilities and weaknesses. Vulnerability scanners are used to generate reports that indicate the areas or aspects of the system that need to be managed to improve security.

wait state

The state in which a process is ready to execute but is waiting for an operation such as keyboard input, printing, or file writing to complete.

war dialing

The act of using a modem to search for a system that will accept inbound connection attempts.

war driving

The act of using a radio wave signal detector or a wireless network detector to locate wireless networks.

warm site

A middle ground between hot sites and cold sites for disaster recovery specialists. A warm site always contains the equipment and data circuits necessary to rapidly establish operations but does not typically contain copies of the client's data.

warning banners

Messages used to inform would-be intruders or attempted security policy violators that their intended activities are restricted and that any further activities will be audited and monitored. A warning banner is basically an electronic equivalent of a no-trespassing sign.

watermarking

The process of digital watermarking hides information within a file that is known only to the file's creator. If someone later creates an unauthorized copy of the content, the watermark can be used to detect the copy and (if uniquely watermarked files are provided to each original recipient) trace the offending copy back to the source.

web application firewall

An Application layer firewall configured specifically to protect against web-based attacks and exploitations.

web bot

Agents that continuously crawl a variety of websites retrieving and processing data on behalf of the user.

webcasting

A form of media distribution occurring over the Internet (in contrast to more traditional means such as over-the-air or cable TV broadcasts and radio stations). Can also include and is related to videocasting, audiocasting, podcasting, netcasting, Internet television, and IP TV.

web vulnerability scanning

See vulnerability scan.

well-known ports

The first 1,024 ports of TCP and UDP. They are usually assigned to commonly used services and applications.

wet pipe system

A fire suppression system that is always full of water. Water discharges immediately when triggered by a fire or smoke. Also known as a closed head system.

whaling

A form of phishing that targets specific high-level executives such as CEOs and presidents.

white box testing

A form of program testing that examines the internal logical structures of a program.

white box

Device used to control the phone system. A white box is a dual-tone multifrequency (DTMF) generator (that is, a keypad).

wide area network (WAN)

A network or a network of LANs that is geographically diverse. Often dedicated leased lines are used to establish connections between distant components.

Wi-Fi Protected Access (WPA)

An early alternative to WEP based on a secret passphrase and employing the LEAP and TKIP crypto systems. It is attackable through passphrase guessing.

WiMax (802.16)

A wireless standard that defines citywide wireless access technologies. This standard has yet to be widely deployed.

Wired Equivalent Privacy (WEP)

A form of encrypted authentication that employs RC4. WEP supports only one-way authentication from client to WAP. WEP is considered insufficient for security because of several deficiencies in its design and implementation.

wired extension mode

A wireless network configuration where the wireless access point acts as a connection point to link the wireless clients to the wired network.

Wireless Application Protocol (WAP)

A functioning industry-driven protocol stack that allows users through their WAP-capable devices, such as mobile phones, to communicate over a carrier's network with the Internet.

wireless networking (802.11)

A form of networking that uses radio waves as the connection medium following the 802.11 standard. Often called Wi-Fi.

wiring closet

The room where the networking cables for a whole building or just a floor are connected to other essential equipment, such as patch panels, switches, routers, LAN extenders, backbone channels, and so on. A more technical name for wiring closet is premises wire distribution room.

work function or work factor

A way of measuring the strength of a cryptography system by measuring the effort in terms of cost and/or time. Usually the time and effort required to perform a complete brute-force attack against an encryption system is what the work function rating represents. The security and protection offered by a cryptosystem is directly proportional to the value of the work function/factor.

worm

A form of malicious code that is self-replicating but is not designed to impose direct harm on host systems. The primary purpose of a worm is to replicate itself to other systems and gather information. Worms are usually very prolific and often cause a denial of service because of their consumption of system resources and network bandwidth in their attempt to self-replicate.

X.25

An older WAN protocol that uses carrier switching to provide end-to-end connections over a shared network medium.

XML

See Extensible Markup Language (XML).

XOR

A function that returns a true value when only one of the input values is true. If both values are false or both values are true, the output of the XOR function is false.

XSRF

See cross-site request forgery (CSRF).

zero day exploit

An attack on a system that exploits vulnerabilities that are unknown to others. Typically, it indicates that a vulnerability known to one or more attackers isn'tAn attack on a system that exploits vulnerabilities that are unknown to others. Typically, it indicates that a vulnerability known to one or more attackers isn't known to the vendor. In some cases the vendor may know about the vulnerability but hasn't written or released a patch for the vulnerability yet.

zero knowledge proof

A concept of communication whereby a specific type of information is exchanged but no real data is exchanged. Good examples of this idea are digital signatures and digital certificates.

zero-knowledge teams

These possess only primary information about an organization during a security assessment or penetration test.

zzuf

A software testing tool that automates the process of mutation fuzzing by manipulating input according to user specifications.