API security is a key component of modern web application security. APIs may have vulnerabilities like broken authentication and authorization, lack of rate limiting, and code injection. Organizations must regularly test APIs to identify vulnerabilities, and address these vulnerabilities using security best practices.
REST APIs do not have any built-in security capabilities—security depends on the design of the API itself.
Security must be built in for data transmission, deployment, and interaction with clients.
REST APIs do not have built-in error handling and need to resend data when an error occurs.
A common architectural choice is to deploy REST APIs behind an API gateway. Clients connect to the gateway, which acts as a proxy, not directly to the REST API. This allows many security concerns to be addressed by the API gateway.
API development has increased astronomically in the past few years, fueled by digital transformation and the central role APIs play in both mobile apps and IoT.
This growth is making API security a top concern. Given the critical role they play in digital transformation—and the access to sensitive data and systems they provide—APIs warrant a dedicated approach to security and compliance.
Because you only control your own APIs, API security centers on securing the APIs you expose either directly or indirectly. API security is less focused on the APIs you consume that are provided by other parties, though analyzing outgoing API traffic can also reveal valuable insights and should be applied whenever possible.
It’s also important to note that API security as a practice overlaps various teams and systems. API security encompasses network security concepts such as rate limiting and throttling, as well as concepts from data security, identity-based security and monitoring/analytics.
The SOAP style of security is applied at the message level using digital signatures and encrypted parts within the XML message itself. Decoupled from the transport layer, it has the advantage of being portable between network protocols (e.g., switching from HTTP to JMS). But this type of message-level security has fallen out of favor and is mostly encountered only with legacy web services that have survived without evolving.
Hackers are users, too
Applying sophisticated access control rules can give you the illusion that the hacker is a valid user. The hacker may be an insider or may have signed up to the application using a fake email address or a social media account.
Valid account, valid credentials
Attackers have many ways to get access to valid credentials, from credential stuffing to buying them on the dark web. Because they know users reuse passwords, hackers can take over legitimate accounts, effectively bypassing the first layer of access control rules.
Stolen token
OAuth token can be leaked through phishing, public repos on GitHub and other ways. Since the vast majority of token confirmations are lightweight bearer tokens, this type of leaked token can be used from anywhere and by anyone until it expires.
Outside-the-app scenarios
Bypassing the client-side app, hackers poke around to find hidden vulnerabilities in your API. These vulnerabilities are hidden to the API provider as well.
These are persistent API security risks. While they may be reduced by tightening security procedures, the risk never really goes away. The key to mitigating these risks is to leverage AI to detect anomalies as described earlier.
Hackers are users, too
Applying sophisticated access control rules can give you the illusion that the hacker is a valid user. The hacker may be an insider or may have signed up to the application using a fake email address or a social media account.
Valid account, valid credentials
Attackers have many ways to get access to valid credentials, from credential stuffing to buying them on the dark web. Because they know users reuse passwords, hackers can take over legitimate accounts, effectively bypassing the first layer of access control rules.
Stolen token
OAuth token can be leaked through phishing, public repos on GitHub and other ways. Since the vast majority of token confirmations are lightweight bearer tokens, this type of leaked token can be used from anywhere and by anyone until it expires.
Outside-the-app scenarios
Bypassing the client-side app, hackers poke around to find hidden vulnerabilities in your API. These vulnerabilities are hidden to the API provider as well.
These are persistent API security risks. While they may be reduced by tightening security procedures, the risk never really goes away. The key to mitigating these risks is to leverage AI to detect anomalies as described earlier.
Testing APIs is a complex and difficult task. The difficulty lies in the fact that there are usually a great number of possible states the API may end up in depending on the traffic. Developers typically test for the use cases they built the API for and limit the amount of testing for situations that fall outside those use cases. That often leads to launching an API with security vulnerabilities still present. There are tools designed to identify design and coding flaws before you go to production—and they should be used—but your testing should extend beyond their use to limit your exposure to hackers. Planning for possible API security vulnerabilities is the best course of action.
Web API security starts with proper authentication and authorization. After a user has been authenticated and has access to the web API, authorization is designed to limit the user’s access to data and other resources. Even if authentication and authorization are in place, enterprises need to ensure users are not misusing, abusing or hacking the API. API security tools are emerging to track API sessions and identify abnormal behavior. They can be used very effectively to deliver audit and forensic data, as well as flag when a hacker might be working on reverse engineering your API to breach the organization.
An insecure API gives individuals access to resources without properly authenticating and/or authorizing access.
-Without authentication, insecure APIs allow anyone, or the wrong people, to access applications, enterprise systems, data and other resources.
-Even if authentication exists, the lack of an effective authorization process means any authenticated users can easily access enterprise systems, data and other resources, even when they should not have permission to access.
