OWASP Top 10

The Open Web Application Security Project (OWASP) has published a new version of its infamous Top 10 vulnerability ranking, four years after its last update, in 2013.

The OWASP Top 10 is not an official document or a standard, but only an awareness document that has been widely adopted as a guideline for classifying the severity of web-based security bugs, and is currently used by many bug bounty platforms and enterprise security teams to assess bug reports.

The OWASP has seen several iterations over the years. Versions of the OWASP Top 10 have been released in 2004, 2007, 2010, 2013, and 2017, respectively.

As in previous years, injection remained the top application security risk, but there has been some shuffling in the ranking, with the appearance of three newcomers — XML External Entities (XXE), Insecure Deserialization, and Insufficient Logging&Monitoring.

Also as in previous years, the ranking was compiled based on user submissions and open discussions.

Below is a list describing each flaw, along with tables comparing the OWASP 2017 Top 10 with older iterations.

OWASP Top 10 2017-2013 changes

A1:2017-Injection
Injection flaws, such as SQL, NoSQL, OS, and LDAP injection, occur when untrusted data is sent to an interpreter as part of a command or query. The attacker’s hostile data can trick the interpreter into executing unintended commands or accessing data without proper authorization.
A2:2017-Broken Authentication
Application functions related to authentication and session management are often implemented incorrectly, allowing attackers to compromise passwords, keys, or session tokens, or to exploit other implementation flaws to assume other users’ identities temporarily or permanently.
A3:2017-Sensitive Data Exposure
Many web applications and APIs do not properly protect sensitive data, such as financial, healthcare, and PII. Attackers may steal or modify such weakly protected data to conduct credit card fraud, identity theft, or other crimes. Sensitive data may be compromised without extra protection, such as encryption at rest or in transit, and requires special precautions when exchanged with the browser.
A4:2017-XML External Entities (XXE)
Many older or poorly configured XML processors evaluate external entity references within XML documents. External entities can be used to disclose internal files using the file URI handler, internal file shares, internal port scanning, remote code execution, and denial of service attacks.
A5:2017-Broken Access Control
Restrictions on what authenticated users are allowed to do are often not properly enforced. Attackers can exploit these flaws to access unauthorized functionality and/or data, such as access other users' accounts, view sensitive files, modify other users’ data, change access rights, etc.
A6:2017-Security Misconfiguration
Security misconfiguration is the most commonly seen issue. This is commonly a result of insecure default configurations, incomplete or ad hoc configurations, open cloud storage, misconfigured HTTP headers, and verbose error messages containing sensitive information. Not only must all operating systems, frameworks, libraries, and applications be securely configured, but they must be patched and upgraded in a timely fashion.
A7:2017-Cross-Site Scripting (XSS)
XSS flaws occur whenever an application includes untrusted data in a new web page without proper validation or escaping, or updates an existing web page with user-supplied data using a browser API that can create HTML or JavaScript. XSS allows attackers to execute scripts in the victim’s browser which can hijack user sessions, deface web sites, or redirect the user to malicious sites.
A8:2017-Insecure Deserialization
Insecure deserialization often leads to remote code execution. Even if deserialization flaws do not result in remote code execution, they can be used to perform attacks, including replay attacks, injection attacks, and privilege escalation attacks.
A9:2017-Using Components with Known Vulnerabilities
Components, such as libraries, frameworks, and other software modules, run with the same privileges as the application. If a vulnerable component is exploited, such an attack can facilitate serious data loss or server takeover. Applications and APIs using components with known vulnerabilities may undermine application defenses and enable various attacks and impacts.
A10:2017-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, and tamper, extract, or destroy data. Most breach studies show time to detect a breach is over 200 days, typically detected by external parties rather than internal processes or monitoring.
2017 2013 2010 2007 2004
Injection Injection Injection Cross-Site Scripting (XSS) Unvalidated Input
Broken Authentication Broken Authentication and Session Management Cross-Site Scripting (XSS) Injection Flaws Broken Access Control
Sensitive Data Exposure Cross-Site Scripting (XSS) Broken Authentication and Session Management Malicious File Execution Broken Authentication and Session Management
XML External Entities (XXE) Insecure Direct Object References Insecure Direct Object References Insecure Direct Object Reference Cross Site Scripting
Broken Access Control Security Misconfiguration Cross-Site Request Forgery (CSRF) Cross-Site Request Forgery (CSRF) Buffer Overflow
Security Misconfiguration Sensitive Data Exposure Security Misconfiguration Information Leakage and Improper Error Handling Injection Flaws
Cross-Site Scripting (XSS) Missing Function Level Access Control Insecure Cryptographic Storage Broken Authentication and Session Management Improper Error Handling
Insecure Deserialization Cross-Site Request Forgery (CSRF) Failure to Restrict URL Access Insecure Cryptographic Storage Insecure Storage
Using Components with Known Vulnerabilities Using Components with Known Vulnerabilities Insufficient Transport Layer Protection Insecure Communications Application Denial of Service
Insufficient Logging & Monitoring Unvalidated Redirects and Forwards Unvalidated Redirects and Forwards Failure to Restrict URL Access Insecure Configuration Management