A1-InjectionInjection 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.Use stored Procs or an ORM
A2-Broken Authentication and Session ManagementApplication functions related to authentication and session management 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.Use SSOs rather than storing passwords yourself. Avoid using Session (it's compromisable). Avoid storing more than than the Session Token in Cookies (ie no Roles) (but see suggestions regarding CSRF below). Use SafeString for password handling. Use displaying UserName everywhere.
A3-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.Avoid architectures that save HTML, preferring Markdown editors or similar. Use XSS libraries to validate posts.
A4-Insecure Direct Object ReferencesA direct object reference occurs when a developer exposes a reference to an internal implementation object, such as a file, directory, or database key. Without an access control check or other protection, attackers can manipulate these references to access unauthorized data.Don't expose a Model directly - use DTOs. Don't expose Model Identities directly - use XOR'ed Ids. Allow for Partial postbacks to not have to hide/leak in the form unneccessary data - prefer nullable DTOs.
A5-Security MisconfigurationGood 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.Have good process. Consider an in-app messaging system or dashboard to alert about expiring certs licenses or dead connections.
A6-Sensitive Data ExposureMany 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.Prefer not having data. If you have to store something, prefer comparing against Hashed data over comparing plain text data. If you have to have the data itself, prefer encrypted data. If you have to encrypt it, prefer salt-ed encrypted data. If you have to prefer salt-ed encrypted data, update the salt each time.
A7-Missing Function Level Access ControlMost web applications verify function level access rights before making that functionality visible in the UI. However, applications need to perform the same access control checks on the server when each function is accessed. If requests are not verified, attackers will be able to forge requests in order to access functionality without proper authorization.Authorize your Service Facade. It's your only important line of authz defences. The UI is just eye-candy.
A8-Cross-Site Request Forgery (IT:AD:Cross Site Request Forgery (CSRF/XSRF))A IT:AD:Cross Site Request Forgery (CSRF/XSRF) attack forces a logged-on victim’s browser to send a forged HTTP request, including the victim’s session cookie and any other automatically included authentication information, to a vulnerable web application. This allows the attacker to force the victim’s browser to generate requests the vulnerable application thinks are legitimate requests from the victim.Avoid reliance solely on cookies, especially in a SPA/ application.
A9-Using Components with Known VulnerabilitiesComponents, 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.Use, upgrade components often.
A10-Unvalidated Redirects and ForwardsWeb applications frequently redirect and forward users to other pages and websites, and use untrusted data to determine the destination pages. Without proper validation, attackers can redirect victims to phishing or malware sites, or use forwards to access unauthorized pages.