Ahtri 12, 10151 Tallinn, Estonia

OWASP API Top 10

OWASP API Top 10
The Open Web Application Security Project – API
API1:2019 Broken Object Level Authorization

APIs tend to expose endpoints that handle object identifiers, creating a wide attack surface
Level Access Control issue. Object level authorization checks should be considered in every function that accesses a data source using an input from the user.

API2:2019 Broken User Authentication

Authentication mechanisms are often implemented incorrectly, allowing attackers to
compromise authentication tokens or to exploit implementation flaws to assume other user’s identities temporarily or permanently. Compromising system’s ability to identify the client/ user, compromises API security overall.

API3:2019 Excessive Data Exposure

Looking forward to generic implementations, developers tend to expose all object properties without considering their individual sensitivity, relying on clients to perform the data filtering before displaying it to the user.

API4:2019 Lack of Resources & Rate Limiting

Quite often, APIs do not impose any restrictions on the size or number of resources that can
be requested by the client/user. Not only can this impact the API server performance, leading to Denial of Service (DoS), but also leaves the door open to authentication flaws such as brute force.

API5:2019 Broken Function Level Authorization

Complex access control policies with different hierarchies, groups, and roles, and an unclear
separation between administrative and regular functions, tend to lead to authorization flaws. By exploiting these issues, attackers gain access to other users’ resources and/or administrative functions.

API6:2019 Mass Assignment

Binding client provided data (e.g., JSON) to data models, without proper properties filtering
based on a whitelist, usually lead to Mass Assignment. Either guessing objects properties, exploring other API endpoints, reading the documentation, or providing additional object properties in request payloads, allows attackers to modify object properties they are not supposed to.

API7:2019 Security Misconfiguration

Security misconfiguration is commonly a result of insecure default configurations,
incomplete or ad-hoc configurations, open cloud storage, misconfigured HTTP headers, unnecessary HTTP methods, permissive Cross-Origin resource sharing (CORS), and verbose error messages containing sensitive information.

API8:2019 Injection

Injection flaws, such as SQL, NoSQL, Command Injection, etc., occur when untrusted data
is sent to an interpreter as part of a command or query. The attacker’s malicious data can trick the interpreter into executing unintended commands or accessing data without proper authorization.

API9:2019 Improper Assets Management

APIs tend to expose more endpoints than traditional web applications, making proper and updated documentation highly important. Proper hosts and deployed API versions inventory also play an important role to mitigate issues such as deprecated API versions and exposed debug endpoints.

API10:2019 Insufficient Logging & Monitoring

Insufficient logging and monitoring, coupled with missing or ineffective integration with
incident response, allows attackers to further attack systems, maintain persistence, pivot to more systems to tamper with, extract, or destroy data. Most breach studies demonstrate the time to detect a breach is over 200 days, typically detected by external parties rather than internal processes or monitoring.


Privacy Preferences
When you visit our website, it may store information through your browser from specific services, usually in form of cookies. Here you can change your privacy preferences. Please note that blocking some types of cookies may impact your experience on our website and the services we offer.