View source for Exploit (computer security)

{{Short description|Method of attack on computer systems}}
{{Lead too long|date=August 2024}}
An '''exploit''' is a method or piece of code that takes advantage of [[Vulnerability (computer security)|vulnerabilities]] in [[software]], [[Application software|applications]], [[Computer network|networks]], [[operating systems]], or [[Computer hardware|hardware]], typically for malicious purposes.
The term "exploit" derives from the English verb "to exploit," meaning "to use something to one’s own advantage."
Exploits are designed to identify flaws, bypass security measures, gain unauthorized access to systems, take control of systems, install [[malware]], or [[data breach|steal sensitive data]].
While an exploit by itself may not be a [[malware]], it serves as a vehicle for delivering malicious software by breaching [[security controls]].<ref name=avast-202-09-29>
{{cite web | last = Latto | first = Nica | title = Exploits: What You Need to Know | website = Exploits: What You Need to Know | date = 2020-09-29 | url = https://www.avast.com/c-exploits | access-date = 2024-08-12 | archiveurl = https://web.archive.org/web/20240515153218/https://www.avast.com/c-exploits | archivedate = 2024-05-15 | url-status = live | quote = An exploit is any attack that takes advantage of vulnerabilities in applications, networks, operating systems, or hardware. Exploits usually take the form of software or code that aims to take control of computers or steal network data. }}</ref><ref name=Cisco-2023-10-06>
{{cite web | title = What Is an Exploit? | website = Cisco | date = 2023-10-06 | url = https://www.cisco.com/c/en/us/products/security/advanced-malware-protection/what-is-exploit.html | access-date = 2024-08-12 | archiveurl = https://web.archive.org/web/20240531021442/https://www.cisco.com/c/en/us/products/security/advanced-malware-protection/what-is-exploit.html | archivedate = 2024-05-31 | url-status = live | quote = An exploit is a program, or piece of code, designed to find and take advantage of a security flaw or vulnerability in an application or computer system, typically for malicious purposes such as installing malware. An exploit is not malware itself, but rather it is a method used by cybercriminals to deliver malware.}}</ref><ref name=Cybersecurity-2019>
{{cite book | last1 = Gonzalez | first1 = Joaquin Jay III | last2 = Kemp | first2 = Roger L. | title = Cybersecurity: Current Writings on Threats and Protection | publisher = McFarland & Company | publication-place = Jefferson, North Carolina | date = 2019-01-25 | isbn = 978-1-4766-3541-5 | page = 241 | url = https://books.google.com/books?id=yyqFDwAAQBAJ&dq=%22A+technique+to+breach+the+security+of+a+network+or+information+system+in+violation+of+security+policy%22&pg=PA241 | quote = A technique to breach the security of a network or information system in violation of security policy.}}</ref><ref name=OWASP>
{{cite web | title = OWASP Secure Coding Practices | website = OWASP Foundation | url = https://owasp.org/www-project-secure-coding-practices-quick-reference-guide/stable-en/03-appendices/05-glossary | access-date = 2024-08-12 | archiveurl = https://web.archive.org/web/20240106035619/https://owasp.org/www-project-secure-coding-practices-quick-reference-guide/stable-en/03-appendices/05-glossary | archivedate = 2024-01-06 | url-status = live | quote = To take advantage of a vulnerability. Typically this is an intentional action designed to compromise the software's security controls by leveraging a vulnerability.}}</ref>
Exploits target vulnerabilities, which are essentially flaws or weaknesses in a system's defenses.
Common targets for exploits include [[operating systems]], [[web browsers]], and various [[Application software|applications]], where hidden vulnerabilities can compromise the integrity and [[Computer security|security]] of [[computer systems]].
Exploits can cause unintended or unanticipated behavior in systems, potentially leading to severe [[security breaches]].<ref name=MWB-2024-04-15>
{{cite web | title = Exploit Definition | website = Malwarebytes | date = 2024-04-15 | url = https://www.malwarebytes.com/exploits | access-date = 2024-08-12 | archiveurl = https://web.archive.org/web/20240516063544/https://www.malwarebytes.com/exploits | archivedate = 2024-05-16 | url-status = live | quote = A computer exploit is a type of malware that takes advantage of bugs or vulnerabilities, which cybercriminals use to gain illicit access to a system. These vulnerabilities are hidden in the code of the operating system and its applications just waiting to be discovered and put to use by cybercriminals. Commonly exploited software includes the operating system itself, browsers, Microsoft Office, and third-party applications. }}</ref><ref name=mitre-2020-10-15>
{{cite web | title = Obtain Capabilities: Exploits, Sub-technique T1588.005 | website = MITRE ATT&CK® | date = 2020-10-15 | url = https://attack.mitre.org/techniques/T1588/005/ | access-date = 2024-08-12 | archiveurl = https://web.archive.org/web/20240524110426/https://attack.mitre.org/techniques/T1588/005/ | archivedate = 2024-05-24 | url-status = live | quote = Adversaries may buy, steal, or download exploits that can be used during targeting. An exploit takes advantage of a bug or vulnerability in order to cause unintended or unanticipated behavior to occur on computer hardware or software. }}</ref>
Many exploits are designed to provide [[superuser]]-level access to a computer system.
Attackers may use multiple exploits in succession to first gain low-level access and then [[Privilege escalation|escalate privileges]] repeatedly until they reach the highest administrative level, often referred to as "root."
This technique of chaining several exploits together to perform a single attack is known as an exploit chain.
Exploits that remain unknown to everyone except the individuals who discovered and developed them are referred to as zero-day or "0day" exploits.
After an exploit is disclosed to the authors of the affected software, the associated vulnerability is often fixed through a [[Patch (computing)|patch]], rendering the exploit unusable.
This is why some [[Black hat (computer security)|black hat hackers]], as well as military or intelligence agency hackers, do not publish their exploits but keep them private.
One scheme that offers zero-day exploits is known as [[exploit as a service]].<ref name=EAA_1>{{cite web| title=Exploit-as-a-service: Cybercriminals exploring potential of leasing out zero-day vulnerabilities| author=Leyden, J.| url=https://portswigger.net/daily-swig/exploit-as-a-service-cybercriminals-exploring-potential-of-leasing-out-zero-day-vulnerabilities| publisher=PortSwigger Ltd| date=16 November 2021| access-date=18 December 2023}}</ref>
Researchers estimate that malicious exploits cost the [[global economy]] over US$450 billion annually.
In response to this threat, organizations are increasingly utilizing [[cyber threat intelligence]] to identify vulnerabilities and prevent hacks before they occur.<ref>{{Cite journal | last1 = Indiana University, Bloomington | last2 = Samtani | first2 = Sagar | last3 = Chai | first3 = Yidong | last4 = Hefei University of Technology | last5 = Chen | first5 = Hsinchun | last6 = University of Arizona | date = 2022-05-24 | title = Linking Exploits from the Dark Web to Known Vulnerabilities for Proactive Cyber Threat Intelligence: An Attention-Based Deep Structured Semantic Model | url = https://misq.umn.edu/linking-exploits-from-the-dark-web-to-known-vulnerabilities-for-proactive-cyber-threat-intelligence-an-attention-based-deep-structured-semantic-model.html | journal = MIS Quarterly | volume = 46 | issue = 2 | pages = 911–946 | doi = 10.25300/MISQ/2022/15392}}</ref>
==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 or physical 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]]s. Exploits against client applications may also require some interaction with the user and thus may be used in combination with the [[social engineering (security)|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.
Exploitations are commonly categorized and named<ref>{{cite web|title=Exploits Database by Offensive Security|url=https://www.exploit-db.com/|website=www.exploit-db.com}}</ref><ref>{{cite web|title=Exploit Database {{!}} Rapid7|url=https://www.rapid7.com/db/modules/|website=www.rapid7.com}}</ref> by the type of vulnerability they exploit {{Clarify | text = (see [[Vulnerability (computing)|vulnerabilities]] for a list)| date = August 2024 | reason = This should link to the section where there is supposed to be a 'list.'  Which list this is talking about isn't obvious.}}, whether they are local/remote and the result of running the exploit (e.g. [[Elevation of Privilege (computing)|EoP]], [[Denial of Service (computing)|DoS]], [[Spoofing attack|spoofing]]).
=== Zero-click ===
A zero-click attack is an exploit that requires no [[user interaction]] to operate – that is to say, no key-presses or mouse clicks.<ref>{{Cite magazine|title=Sneaky Zero-Click Attacks Are a Hidden Menace|language=en-US|magazine=Wired|url=https://www.wired.com/story/sneaky-zero-click-attacks-hidden-menace/|access-date=2021-09-14|issn=1059-1028}}</ref> [[FORCEDENTRY]], discovered in 2021, is an example of a zero-click attack.<ref>{{Cite magazine|title=The Stealthy iPhone Hacks That Apple Still Can't Stop|language=en-US|magazine=Wired|url=https://www.wired.com/story/apple-imessage-zero-click-hacks/|access-date=2021-09-14|issn=1059-1028}}</ref><ref>{{Cite web|title=A new NSO zero-click attack evades Apple's iPhone security protections, says Citizen Lab|url=https://techcrunch.com/2021/08/24/nso-pegasus-bahrain-iphone-security/|access-date=2021-09-14|website=TechCrunch|date=24 August 2021|language=en-US|archive-date=2021-08-24|archive-url=https://web.archive.org/web/20210824124718/https://social.techcrunch.com/2021/08/24/nso-pegasus-bahrain-iphone-security/|url-status=live}}</ref>
These exploits are commonly the most sought after exploits (specifically on the underground exploit market) because the target typically has no way of knowing they have been compromised at the time of exploitation.
In 2022, [[NSO Group]] was reportedly selling zero-click exploits to governments for breaking into individuals' phones.<ref>{{cite news |journal=Insurance Journal |url=https://www.insurancejournal.com/news/international/2022/02/18/654917.htm |title=Beware of 'Zero-Click' Hacks That Exploit Security Flaws in Phones' Operating Systems |author=Ryan Gallagher |date=February 18, 2022}}</ref>
==Pivoting==
{{Off topic|date=August 2024|Pivoting|Pivoting is a follow-on to an exploit}}
Pivoting is a technique employed by both hackers and [[penetration test]]ers to expand their access within a target network. By compromising a system, attackers can leverage it as a platform to target other systems that are typically shielded from direct external access by [[Firewall (computing)|firewalls]]. Internal networks often contain a broader range of accessible machines compared to those exposed to the internet. For example, an attacker might compromise a web server on a corporate network and then utilize it to target other systems within the same network. This approach is often referred to as a multi-layered attack. Pivoting is also known as ''island hopping''.
Pivoting can further be distinguished into [[Proxy server|proxy]] pivoting and [[VPN]] 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.<ref><!--is this a separate source? Fix (and with separate cite web): [http://www.metasploit.com/redmine/projects/framework/wiki/Pivoting Metasploit Framework Pivoting], -->{{cite web |url=https://www.digitalbond.com/index.php/2010/07/12/metasploit-basics-part-3-pivoting-and-interfaces/ |title=Metasploit Basics – Part 3: Pivoting and Interfaces |work=Digital Bond}}</ref> This type of pivoting is restricted to certain [[Transmission Control Protocol|TCP]] and [[User Datagram Protocol|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 (software)|payload]] 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==
{{refbegin |30em}}
* [[Computer security]]
* [[Computer virus]]
* [[Crimeware]]
* [[Exploit kit]]
* ''[[Hacking: The Art of Exploitation]]'' (second edition)
* [[IT risk]]
* [[Metasploit Project|Metasploit]]
* [[Shellcode]]
* [[w3af]]
{{refend}}
==Notes==
{{reflist}}
==External links==
*{{Commonscat-inline|Computer security exploits}}
{{Authority control}}
{{Information security}}
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[[Category:Computer security exploits| ]]