API Common Attacks and Best Methods to Protect

Vulnerable APIs cause significant breaches. They are easily exploitable and provide hackers access to critical medical, financial, and personal information. Some examples of attacks can occur if an API is not adequately secured.

Broken Object Level Authorization

The most prevalent and damaging API attack is Broken Object Level Authorization. Attackers replace the ID of their resource in the API call with the ID of another user’s resource. They then access the given resource due to a lack of proper authorization checks. IDOR is another name for this attack (Insecure Direct Object Reference).

By changing the ID of an object delivered within the request, attackers can exploit API endpoints subject to broken object-level permission. This might result in unauthorized access to sensitive data.

This problem is widespread in API-based applications since the server component typically does not entirely maintain the client’s status and instead depends on parameters such as object IDs given by the client to determine which objects to access. Unauthorized access can lead to data exposure to unauthorized individuals, data loss, or data tampering. Unauthorized access to objects can also result in a complete account takeover.

Broken Authentication

Unprotected APIs with no authentication poses a significant risk to the organization. Other vulnerabilities related to broken authentication are weak API keys that are not rotated, weak authentication that can be brute-forced, exposing the credential and keys within the API endpoints, and lack of access token digital signature and validation.

API Injection Attack

This attack occurs on an application that runs poorly developed and updated code. To obtain access to your application, the hacker injects harmful code into it, such as SQLi (SQL injection) and XSS (cross-site scripting). APIs with vulnerabilities in authentication and validation are also vulnerable to code injection, which occurs when an attacker sends a script to an application’s server via an API request. This script is designed to disclose or destroy data, plant fake information, and cause damage to the application’s infrastructure.

API Parameter Tampering

API endpoints can be fuzzed and tampered with if the proper input validation is not performed. Parameter tampering is a web-based cyber-attack in which URL parameters / API endpoints variables are modified without server-side knowledge. In some cases, data provided by a user into a form field on a webpage may be updated without the user’s permission.

Excessive Data Exposure

Excessive data exposure occurs when an application delivers more information than is required for a user to accomplish a given activity via an API response. When web and mobile applications rely on API calls that provide more information to the user than is required, the responses reveal unfiltered data that an attacker might exploit by sniffing the network from APIs using Man in the Middle attack to get sensitive information. When sensitive data is exposed in this manner, it can have a severe business impact depending on what data is disclosed, but owing to the nature of the sensitive data, it nearly always has a significant effect.

Denial-of-Service Attack

This is most likely the most prevalent type of attack and is frequently mentioned in the news. A Distributed Denial of Service (DDoS) attack is one in which multiple systems overwhelm the bandwidth of the target system. A DDoS attack against a web API seeks to overrun its memory by simultaneously flooding it with thousands of connections. Hackers can also do this by delivering a massive and heavy quantity of data in each request where no rate-limiting restrictions are applied.
The objective of DoS attacks is not to change, erase, or steal data. The goal is to disrupt the operation of an online service or the reputation of a firm that provides such services. The attackers direct a bot to the API and send a series of high-frequency requests to an endpoint for a set time. The tolerance of requests exceeds the target’s capacity to reply, making it inaccessible to genuine users.

Insufficient Logging and Monitoring

Another major issue with how APIs are designed and developed to generate suitable security-related logs. Most APIs have insufficient logging capabilities; to add to that, real-time security monitoring of APIs is also not performed by many organizations.

Without sufficient API logging and monitoring, attackers can exploit API vulnerabilities with zero knowledge from the organization.

Man-in-the-Middle Attack

A MITM attack is precisely what it sounds like: an attacker stealthily transmits, modifies, and intercepts communications, messages, and requests between two parties to get sensitive information. A hacker can act as a man in the middle for a session token issuing API to an HTTP header and a user. If the hacker intercepts the session token, he will get access to the user’s account, potentially revealing sensitive and personal information.

When a hacker intercepts an API request or response between an end-user and an API, this is known as a man-in-the-middle (MITM) attack. They may steal sensitive communication contents (e.g., account login passwords or payment information) or change the request/response.