Advanced Web Application Attack Techniques

As cyber threats continue to evolve, attackers are employing advanced techniques to target high-value systems and sensitive data. These attacks often involve a combination of stealth, persistence, and precision, posing significant challenges to traditional security measures. This page explores advanced attack types, their techniques, and strategies for defending against them.

Cookie Manipulation/Poisoning

In a cookie poisoning attack, the attacker modifies HTTP cookies’ contents before the user’s browser sends them to a web site. Attackers may use cookie hijacking as a prelude to cookie poisoning so they can access cookie content before altering it, however this is not always required.

Cookie poisoning attacks are fatal because they allow attackers to use the data stored inside cookies to gain unauthorized access to users’ accounts or to steal their identities.

Following are the few ways attackers get hold of the users’ cookie:

• Session Hijacking: The key to session hijacking is obtaining an active session ID from a user who is logged in. If cookies are used to maintain sessions, attackers can obtain session data without authorization by utilizing cookie hijacking techniques.
• Session Fixation: Session fixation occurs when a victim is tricked into logging in with a session ID known by the attacker, with the identifier being generated either by the attacker or the web application.This enables the attacker to later take control of the user’s session. The session ID is produced by the attacker, supplied to the user via social engineering methods, and then placed in a session cookie, therefore cookie poisoning or hijacking is not necessary in this instance.
• Session ID prediction: Session ID prediction makes use of flaws in the way session IDs are produced for a certain site. Attackers can produce legitimate session IDs if the process is not sufficiently random and they are able to decipher the algorithm. Attackers may even employ brute force methods to guess legitimate session identifiers for authentication if they are brief. Although starting a new session with a predicted ID is simpler than using cookie poisoning to change an existing session ID, it is potentially possible.

What causes cookie poisoning?

Cookie poisoning can be done in two ways: at client-side and during transmission.

• Client-side cookie poisoning. Someone who has the ability to alter cookie data before it reaches the server launches this kind of assault.
• Man-in-the-middle cookie hijacking. Here, the attacker acts as a middleman between the client-end web browser and the web server, gains access to the cookie information being transmitted, and then steals or modifies it for malicious benefit.

Preventing cookie poisoning

• Using unique and secure session cookies – Once the session is closed, it’s crucial to make sure that attackers cannot access session identifiers. Additionally, they must to be randomly produced and challenging to crack using brute force or other techniques. .
• Frequent vulnerability scans – By regularly scanning web applications using a vulnerability scanner, security vulnerabilities that may lead to cookie poisoning can be proactively identified and eliminated.
• Limiting multipurpose cookies– Multipurpose cookies create a lot of security risks, so it is important to restrict each cookie for a single task.
• Using Hypertext Transfer Protocol Secure (HTTPS) communication – To ensure safe information flow and lessen the possibility of attackers listening in on cookie content, HTTPS communication is essential.

Fuzzing

Fuzzing is an automated Black Box software testing technique which is used to find implementation bugs using malformed/semi-malformed data injection.

Consider an integer value that a program uses to store the outcome of a user selecting one of three options. When the user selects one, they will have the option of 0, 1, or 2. It results in three use cases. What would happen if we transmitted 3, or 255? Since integers are kept in a static size variable, we can. The application may crash and result in “classical” security problems if the default switch case has not been implemented securely: DoS attacks, vulnerable buffer overflows,…

A testing tool called a fuzzer automatically injects semi-random data into a program or stack to find vulnerabilities.

Generators make up the data generating portion, and debugging tools are used to identify vulnerabilities. Typically, generators combine static fuzzing vectors—known to be harmful values—or completely random data. Genetic algorithms are used by newer generations of fuzzers to connect injected data with impact measurements. These tools are not yet accessible to the general public.

Attack types

A fuzzer would test various attack combinations on:

• Characters (URLs, command-line inputs)
• Numbers (signed/unsigned integers/float…)
• Pure binary sequences

Defining lists of “known-to-be-dangerous values” (fuzz vectors) for each type and injecting them or recombinations is a frequent fuzzing technique.

• For chars: escaped, interpretable characters / instructions (ex: For SQL Requests, quotes / commands…)
• For integers: zero, possibly negative or very big numbers
• For binary: random ones

Dictionary Attack

A dictionary attack entails inputting every word in a dictionary as a password in order to gain access to a password-protected computer, network, or other IT resource. A dictionary attack can also be used to try to decipher a communication or document that has been encrypted.

Unlike a brute force attack, which attempts every combination, a dictionary attack uses a predetermined list of terms.

Dictionary attacks are successful because so many users are using common terms as passwords. These attacks frequently fail when conducted against systems that use multiple-word passwords and passwords made up of random combinations of uppercase, lowercase, and digits and letters.

The brute-force technique of attack, in which every conceivable combination of characters and spaces is examined up to a specific maximum length, can occasionally be successful in systems with strict password restrictions. A brute-force attack can, however, take a while to yield results.

Strong, randomly generated passwords are extremely unlikely to be found in the predetermined password library and cannot be easily predicted. It is virtually impossible to break non predictable passwords using a dictionary attack because guesses can only come from a predetermined list.

Logic Bombs

A logic bomb is a sequence of instructions in a program that can attack an operating system, a program, or a network by delivering a malicious payload. It doesn’t start unless a certain conditions are met. These restrictions can be as straightforward as a particular day or hour. An even more complicated illustration is when a company fires an employee and records the termination in its database.

Until it performs its intended function or releases its payload, a logic bomb usually goes undiscovered. There is practically no limit to the number of conditions that might cause it.

Because its programming is inert until the trigger happens, a logic bomb is cunning. Bombers are able to choose when to launch their attack thanks to this purposeful delay between code insertion and action (payload release). But more crucially, it helps them hide their tracks because the logic bomb frequently goes undetected for weeks or even years.

Backdoor

A backdoor attack circumvents the system’s usual security measures to gain access to a computer system or encrypted information. An application, operating system, or data may have a backdoor created by a developer that allows access for debugging or other purposes. Attackers use backdoors that software developers put in place, as well as backdoors that they put in place as part of a computer hack.

When threat actors utilize a backdoor to gain remote access to a system, they are committing a backdoor attack. These assaults give attackers the ability to take over system resources, explore networks, and install various infections. In certain instances, attackers create a worm or virus to exploit a backdoor that was already present due to an earlier attack or a backdoor developed by the original developers.

Once they have gained access to a system, threat actors may engage in the following destructive activities:

1. Stealing sensitive or important information
2. Hijacking servers
3. Engaging in deceptive activity
4. Installing spyware, keyloggers and Trojan horses
5. Launching denial of service (DoS) attacks
6. Defacing websites.

Session Hi-Jacking

According to OWASP, The Session Hijacking attack compromises the session token by stealing or predicting a valid session token to gain unauthorized access to the Web Server.

There are several ways that the session token could be compromised; the most frequent ones are:

• Using packet sniffing tools
• Predicting session identifier
• Client-side attacks (XSS, malicious JavaScript Code);
• Man-in-the-middle attack
• Man-in-the-browser attack

Defenses against Session Hijacking

1. Avoid using public wi-fi networks
2. Using VPN

Advanced Persistent Threat(APT)

APT stands for Advanced Persistent Threat. An APT is a highly sophisticated and targeted cyberattack in which an unauthorized user gains access to a network and remains undetected for an extended period. The primary characteristics of APTs include advanced tactics, careful planning, and a persistent focus on a specific target, such as a government agency, corporation, or political organization.

Key features of Advanced Persistent Threats include:

1. Sophistication: APTs involve advanced and often custom-built tools and techniques that go beyond typical cyber threats. They are usually orchestrated by skilled and well-funded threat actors.
2. Persistence: APTs are not hit-and-run attacks. The attackers remain within the compromised system for an extended period, sometimes for months or even years, to gather intelligence, monitor activities, and achieve their objectives.
3. Targeted: APTs are directed at specific individuals, organizations, or sectors. The attackers often conduct thorough reconnaissance to understand the target’s vulnerabilities and create tailored strategies.
4. Stealth: APTs are designed to avoid detection by traditional security measures. Attackers use various evasion techniques to remain unnoticed, such as employing encrypted communication channels and exploiting zero-day vulnerabilities.
5. Goals: APTs typically have specific objectives, such as stealing sensitive data, intellectual property, or conducting espionage. Financial gain, political motives, or strategic advantage are common driving forces.
6. Phases: APT attacks often unfold in multiple phases, including initial compromise, establishing a foothold, escalating privileges, maintaining persistence, and achieving the ultimate goal.

Defense against APTs requires a comprehensive and proactive approach, including robust cybersecurity measures, continuous monitoring, threat intelligence, and user education. Organizations need to be vigilant and adapt their security strategies to combat the evolving nature of APTs and the persistent threat they pose.

Also Read: Attack Techniques-Common, Attack Techniques Section