Understanding Web Application And API Attacks

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Web applications and APIs are prevalent across the internet, powering everything from games and software to financial services, travel booking, and online shopping. While they provide great convenience and capabilities, web apps and APIs can also be vulnerable to attacks if not properly secured. In this article, we'll explain some common web application and API attack types and provide examples from different industries.

Cross-site scripting (XSS)

XSS attacks involve injecting malicious client-side scripts into web pages viewed by other users. This allows the attacker to bypass access controls and masquerade as an authorized user. For example, an XSS vulnerability on a gaming site could allow a hacker to hijack other users' accounts by stealing their session cookies. Similarly, an XSS flaw in an eCommerce site's search bar could enable malicious scripts that steal payment info.

SQL injection

Many web apps and APIs rely on backend databases like SQL. SQL injection involves inserting malicious SQL statements into input fields like search bars to gain unauthorized data access or perform damaging queries. For instance, a flawed travel booking site could enable SQL injection to lookup customer payment details. Likewise, bugs in an  app's login form may enable running SQL queries to extract password hashes.

Broken authentication

Authentication mechanisms like login forms are common attack vectors if implemented improperly. Attacks can exploit weak passwords, bypass authentication, or crack stolen password databases. A vulnerable authentication API on a financial platform could allow account takeovers. Gaming sites with broken auth schemes may result in compromised user accounts.

Cross-site request forgery (CSRF)

With CSRF, attackers trick users into making unauthorized state-changing requests on web apps they're logged into. This could allow malicious actions like transferring funds, changing passwords, or modifying permissions. Banks with CSRF flaws could be exploited to initiate wire transfers. Gaming and SaaS sites may have CSRF issues enabling unwanted account changes.

Insecure direct object references

Web apps often expose internal objects like filenames or database keys in URLs. If proper access controls aren't enforced, this could enable information disclosure by accessing objects via guessing identifiers. For example, a financial site may enable viewing other users' statements. A travel API could potentially expose booking details.

Local file inclusion (LFI)

LFI attacks involve exploiting input fields and parameters to make the web app include local files on the server like /etc/passwd. This could expose sensitive system info or be further exploited to remotely execute code. For instance, a gaming site vulnerable to LFI may reveal database credentials or enable system shell access.


The examples above illustrate how common web application vulnerabilities can lead to account takeovers, financial fraud, data leaks, or other impacts if left unaddressed. Proper input validation, authentication mechanisms, access controls, and security testing during development can help mitigate these attack risks. Maintaining ongoing awareness of emerging threats is also key for website operators.

Additionally, techniques like fingerprint services and virtual waiting rooms, when combined with other protections as part of a defense-in-depth strategy, can further help thwart attacks. However, a layered security approach utilizing multiple tools and best practices is essential for reliably protecting web applications and APIs. To learn more about Fingerprint and Virtual Waiting Rooms, schedule a demo with an Enterprise Solutions Architect.

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