• OWASP Top 10 2017

Direct link to the Top 10 list

The Top 10 list is the most popular project of the OWASP community and is often used as the entry point into the application security domain. The list defines 10 biggest security risks the web applications are facing (de facto meaning - 10 most common security problems) and is updated every ~3 years.

OWASP Top 10 list is greatly misused world wide. The purpose of the list is to raise the awareness among developers and inspire the development culture. The Top 10 list is not a standard (that’s what OWASP ASVS is for) and should not be used for security audit or security testing. The list is also insufficient to consider the compliant applications secure.

Still the OWASP Top 10 list compliance can be found among the most common security requirements and customer requests.

OWASP Top 10 2017 defines following risks:

• A1-Injection - Injection flaws, such as SQL, 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. Solutions: S5-4, S5-5, S5-6, S5-8.

• A2-Broken Authentication - Application functions related to authentication are often not implemented correctly, allowing attackers to compromise passwords, keys, or session tokens, or to exploit other implementation flaws to assume other users’ identities. Solutions: S2.

• A3-Sensitive Data Exposure - Many web applications do not properly protect sensitive data, such as credit cards, tax IDs, and authentication credentials. Attackers may steal or modify such weakly protected data to conduct credit card fraud, identity theft, or other crimes. Sensitive data deserves extra protection such as encryption at rest or in transit, as well as special precautions when exchanged with the browser. Solutions: S4, S9, S7-1

• A4-XML External Entities (XXE) - Many older or poorly configured (or simply java-based) 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. Solutions: S5-7

• A5-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. Solutions: S4

• A6-Security Misconfiguration - Good security requires having a secure configuration defined and deployed for the application, frameworks, application server, web server, database server, and platform. Secure settings should be defined, implemented, and maintained, as defaults are often insecure. Additionally, software should be kept up to date. Solutions: This point goes far beyond the scope of this guide, as it addresses problems of the proper server configuration. The application will not be secure, if the servers it is running on are not properly configured (hardened). On of many resources available online that can help to properly configure the servers are the CIS Benchmarks.

• A7-Cross-Site Scripting (XSS) - XSS flaws occur whenever an application takes untrusted data and sends it to a web browser without proper validation or escaping. 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. Solutions: S5-9

• A8-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. Solutions: TODO, as this is not yet covered by OWASP ASVS 3.0.1.

• A9-Using Components with Known Vulnerabilities - Components, such as libraries, frameworks, and other software modules, almost always run with full privileges. If a vulnerable component is exploited, such an attack can facilitate serious data loss or server takeover. Applications using components with known vulnerabilities may undermine application defenses and enable a range of possible attacks and impacts. Solutions: S13-1

• A10-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. Solutions: S5-2, S7, TODO - there should be more than this.