What is an Exploit in Cyber Security – Exploit Database

An exploit in computer security is a piece of software, a chunk of data, or a sequence of commands that takes advantage of a vulnerability in a system or software application to cause unintended or undesirable behaviour. Exploits are often used by attackers to gain unauthorized access to a computer system, install malware, steal sensitive data, or carry out other malicious actions.

The vulnerability that an exploit targets can be caused by a variety of factors, including software bugs, design flaws, misconfigurations, or security weaknesses in the system or application. Once an attacker has successfully exploited a vulnerability, they can often gain control of the affected system, compromise its security, and potentially use it as a launching point for further attacks.

It’s important to regularly update software and systems to address known exploits and vulnerabilities and to implement security measures such as firewalls, intrusion detection and prevention systems, and anti-virus software to help prevent and detect exploits.

There are many different types of exploits that can be used to target vulnerabilities in systems and applications. Some of the most common include:

Buffer overflows: This type of exploit takes advantage of a vulnerability in the way that a system or application handles data input, causing it to overwrite parts of its memory and execute arbitrary code.
Remote code execution: This type of exploit allows an attacker to execute code on a remote system, typically through a network connection or a web application.
SQL injection: This type of exploit targets vulnerabilities in web applications that use SQL databases. By injecting malicious SQL code into a web application, an attacker can manipulate the database and steal or modify data.
Cross-Site Scripting (XSS): This type of exploit allows an attacker to inject malicious scripts into a web page, which are then executed in the browser of anyone visiting the page.
Zero-day exploits: This type of exploit targets vulnerabilities that are unknown to the vendor and are therefore unpatched. Zero-day exploits can be particularly dangerous because they can be used to carry out attacks before the vendor has had a chance to release a patch.

It’s important to be proactive in protecting against exploits by keeping systems and software up to date with the latest security patches, implementing security best practices, and being aware of the latest threats and exploits. Additionally, companies can implement security technologies like firewalls, intrusion detection and prevention systems, and anti-virus software to help protect against exploits and limit the damage caused by successful attacks.

CLASSIFICATION

There are several methods of classifying exploits. The most common is by how the exploit contacts 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 client application. Exploits against client applications may also require some interaction with the user and thus may be used in combination with social engineering method. This is the hacker way of getting into computers and websites for stealing data.

Another classification is by the action against vulnerable system: unauthorized data access, arbitrary code execution, denial of service.

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 root.

Normally a single exploit can only take advantage of a specific software vulnerability. Often, when an exploit is published, the vulnerability is fixed through a patch and the exploit becomes obsolete for newer versions of the software. This is the reason why some blackhat hackers do not publish their exploits but keep them private to themselves or other crackers. Such exploits are referred to as ‘zero day exploits’ and to obtain access to such exploits is the primary desire of unskilled attackers, often nicknamed script kiddies.

TYPES OF EXPLOITS

Exploits are commonly categorized and named by these criteria:

The type of vulnerability they exploit (See the article on vulnerabilities for a list)
Whether they need to be run on the same machine as the program that has the vulnerability (local) or can be run on one machine to attack a program running on another machine (remote).
The result of running the exploit (EoP, DoS, Spoofing, etc.)

PIVOTING

Pivoting refers to method used by penetration testers that uses compromised system to attack other systems on the same network to avoid restrictions such as firewall configurations, which may prohibit direct access to all machines. For example, an attacker compromises a web server on a corporate network, the attacker can then use the compromised web server to attack other systems 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 pivoting and VPN pivoting:

Proxy pivoting: generally describes the practice channeling traffic through a compromised target using a proxy payload on the machine and launching attacks from this computer.[1] 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 2 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 she were behind the firewall.
Typically, the proxy or VPN applications enabling pivoting are executed on the target computer as the payload (software) of an exploit.

Before poking Exploits, you must know the Vulnerabilities associated. Here is a website that Contains list of all Vulnerabilities.

OSVDB << Shutdown due to No Support and Contribution from Industry
NATIONAL VULNERABILITY DATABASE
WINDOWS EXPLOITS
LINUX EXPLOITS
REMOTE EXPLOITS
LOCAL EXPLOITS
WEB APPLICATION EXPLOITS
SHELLCODE

In computer security, 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. Shellcode is commonly written in machine code, 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.