An exploit (from the English verb ''to exploit'', meaning "to use something to one’s own advantage") is a piece of
software
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work.
At the lowest programming level, executable code consists ...
, a chunk of data, or a sequence of commands that takes advantage of a
bug or
vulnerability
Vulnerability refers to "the quality or state of being exposed to the possibility of being attacked or harmed, either physically or emotionally."
A window of vulnerability (WOV) is a time frame within which defensive measures are diminished, com ...
to cause unintended or unanticipated behavior to occur on computer software, hardware, or something electronic (usually computerized). Such behavior frequently includes things like gaining control of a computer system, allowing
privilege escalation
Privilege escalation is the act of exploiting a bug, a design flaw, or a configuration oversight in an operating system or software application to gain elevated access to resources that are normally protected from an application or user. The res ...
, or a
denial-of-service (DoS or related DDoS) attack. In lay terms, some exploit is akin to a 'hack'.
Classification
There are several methods of classifying exploits. The most common is by how the exploit communicates to the vulnerable software.
A ''remote exploit'' works over a network and exploits the security vulnerability without any prior access to the vulnerable system.
A ''local exploit'' requires prior access to the vulnerable system and usually increases the privileges of the person running the exploit past those granted by the system administrator. Exploits against client applications also exist, usually consisting of modified servers that send an exploit if accessed with a client application. A common form of exploits against client applications are
browser exploit
A browser exploit is a form of malicious code that takes advantage of a flaw or vulnerability in an operating system or piece of software with the intent to breach browser security to alter a user's browser settings without their knowledge. Malici ...
s.
Exploits against client applications may also require some interaction with the user and thus may be used in combination with the
social engineering method. Another classification is by the action against the vulnerable system; unauthorized data access, arbitrary code execution, and denial of service are examples.
Many exploits are designed to provide superuser-level access to a computer system. However, it is also possible to use several exploits, first to gain low-level access, then to escalate privileges repeatedly until one reaches the highest administrative level (often called "root").
After an exploit is made known to the authors of the affected software, the vulnerability is often fixed through a patch and the exploit becomes unusable. That is the reason why some
black hat
Black hat, blackhats, or black-hat refers to:
Arts, entertainment, and media
* Black hat (computer security), a hacker who violates computer security for little reason beyond maliciousness or for personal gain
* Black hat, part of black and white ...
hackers
A hacker is a person skilled in information technology who uses their technical knowledge to achieve a goal or overcome an obstacle, within a computerized system by non-standard means. Though the term ''hacker'' has become associated in popu ...
as well as military or intelligence agencies' hackers do not publish their exploits but keep them private.
Exploits unknown to everyone except the people that found and developed them are referred to as ''
zero day exploits''.
Types
Exploitations are commonly categorized and named by the type of vulnerability they exploit (see
vulnerabilities
Vulnerability refers to "the quality or state of being exposed to the possibility of being attacked or harmed, either physically or emotionally."
A window of vulnerability (WOV) is a time frame within which defensive measures are diminished, com ...
for a list), whether they are local/remote and the result of running the exploit (e.g.
EoP,
DoS
DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems.
DOS may also refer to:
Computing
* Data over signalling (DoS), multiplexing data onto a signalling channel
* Denial-of-service attack (DoS), an attack on a communicat ...
,
spoofing). One scheme that offers zero day exploits is
Exploit-as-a-service.
Zero-click
A zero-click attack is an exploit that requires no
user interaction
Ancient Egyptian roles
* User (ancient Egyptian official), an ancient Egyptian nomarch (governor) of the Eighth Dynasty
* Useramen, an ancient Egyptian vizier also called "User"
Other uses
* User (computing), a person (or software) using an ...
to operate – that is to say, no key-presses or mouse clicks.
FORCEDENTRY, discovered in 2021, is an example of a zero-click attack.
In 2022,
NSO Group
NSO Group Technologies (NSO standing for Niv, Shalev and Omri, the names of the company's founders) is an Israeli cyber-intelligence firm primarily known for its proprietary spyware Pegasus, which is capable of remote zero-click surveillance ...
was reportedly selling zero-click exploits to governments for breaking into individuals' phones.
Pivoting
Pivoting is a method used by hackers and
penetration test
A penetration test, colloquially known as a pen test or ethical hacking, is an authorized simulated cyberattack on a computer system, performed to evaluate the security of the system; this is not to be confused with a vulnerability assessment. T ...
ers to expand the attack surface of a target organization. A compromised system to attack other systems on the same network that are not directly reachable from the Internet due to restrictions such as
firewall
Firewall may refer to:
* Firewall (computing), a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts
* Firewall (construction), a barrier inside a building, designed to limit the spre ...
. There tends to be more machines reachable from inside a network as compared to Internet facing hosts. For example, if an attacker compromises a web server on a corporate network, the attacker can then use the compromised web server to attack any reachable system on the network. These types of attacks are often called multi-layered attacks. Pivoting is also known as ''island hopping''.
Pivoting can further be distinguished into
proxy
Proxy may refer to:
* Proxy or agent (law), a substitute authorized to act for another entity or a document which authorizes the agent so to act
* Proxy (climate), a measured variable used to infer the value of a variable of interest in climate ...
pivoting and
VPN
A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The be ...
pivoting:
* Proxy pivoting is the practice of channeling traffic through a compromised target using a proxy payload on the machine and launching attacks from the computer.
This type of pivoting is restricted to certain
TCP and
UDP ports that are supported by the proxy.
* VPN pivoting enables the attacker to create an encrypted layer to tunnel into the compromised machine to route any network traffic through that target machine, for example, to run a vulnerability scan on the internal network through the compromised machine, effectively giving the attacker full network access as if they were behind the firewall.
Typically, the proxy or VPN applications enabling pivoting are executed on the target computer as the
payload
Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...
of an exploit.
Pivoting is usually done by infiltrating a part of a network infrastructure (as an example, a vulnerable printer or thermostat) and using a scanner to find other devices connected to attack them. By attacking a vulnerable piece of networking, an attacker could infect most or all of a network and gain complete control.
See also
*
Computer security
Computer security, cybersecurity (cyber security), or information technology security (IT security) is the protection of computer systems and networks from attack by malicious actors that may result in unauthorized information disclosure, the ...
*
Computer virus
A computer virus is a type of computer program that, when executed, replicates itself by modifying other computer programs and inserting its own code. If this replication succeeds, the affected areas are then said to be "infected" with a compu ...
*
Crimeware
Crimeware is a class of malware designed specifically to automate cybercrime.
Crimeware (as distinct from spyware and adware) is designed to perpetrate identity theft through social engineering or technical stealth in order to access a comput ...
*
Exploit kit
An exploit kit is a tool used for automatically managing and deploying exploits against a target computer. Exploit kits allow attackers to deliver malware without having advanced knowledge of the exploits being used. Browser exploits are typica ...
* ''
Hacking: The Art of Exploitation'' (second edition)
*
IT risk
Information technology risk, IT risk, IT-related risk, or cyber risk is any risk related to information technology. While information has long been appreciated as a valuable and important asset, the rise of the knowledge economy and the Digital Re ...
*
Metasploit
The Metasploit Project is a computer security project that provides information about security vulnerabilities and aids in penetration testing and IDS signature development. It is owned by Boston, Massachusetts-based security company Rapid7.
It ...
*
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 m ...
*
w3af
w3af (Web Application Attack and Audit Framework) is an open-source web application security scanner. The project provides a vulnerability scanner and exploitation tool for Web applications. It provides information about security vulnerabilities ...
Notes
External links
*
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