OWASP Periodic Table of Vulnerabilities - Cookie Theft/Session Hijacking
Cookie Theft/Session Hijacking
Root Cause Summary
It's possible for an attacker to steal and reuse session identifiers or other sensitive cookie values when they are stored or transmitted insecurely.
Browser / Standards Solution
Define a new standard for transmitting session identifiers and managing them within the browser, such as a new request/response header to be used instead of cookies. The standard should include a mechanism to tie the session identifier to the SSL session on both the browser and the server.
- Make sure that all session identifiers are transmitted over an encrypted protocol.
- Terminate/regenerate the session if the session token is transmitted insecurely (either in clear text or as part of the URL), or signal to the application to do so.
- Enforce the Secure and HttpOnly flags on sensitive cookies using a Web Application Firewall.
- Ensure that session identifiers are transmitted only using the SSL session where they originated. Track sessions across SSL renegotiations and integrate with framework solutions to support common SSL termination/reencryption architectures.
Generic Framework Solution
The framework should provide a centralized cookie management API which prevents direct access to cookies. By default, cookies should be handled according to the following rules, which must be explicitly overridden if a developer has a specific need for a cookie with unsafe properties.
- Apply Secure and HttpOnly flags.
- Set the Domain and Path parameters for the cookie correctly.
- Automatically check for cookie support and either instruct the user to enable cookies/upgrade the browser, or switch to a "cookieless" session scheme based on a configuration choice. Default to requiring cookie support.
- Expose a simple administrative interface for setting P3P rules.
- Automatically validate and signal when the number of cookies in use or the size of cookie data exceeds that which is commonly supported by browsers.
- Prevent application code from overwriting or otherwise manipulating the session cookie. Possibly prohibit the application from accessing the session token at all.
The framework should provide a configurable session management scheme, which includes the following features:
- Alert user and deauthorize oldest session when multiple simultaneous logins are detected. Multiple simultaneous logins are prohibited by default, but may be enabled by changing a configuration setting.
- Terminate session and send security SNMP trap or other configurable message if User-Agent string or other client fingerprinting changes.
- Tie the session ID to the SSL session and provide configurable options for actions to take if the session ID is transmitted over a new SSL session. Expose integration points with perimeter technologies to facilitate SSL termination, renegotiation, and other transitions.
- Provide the option to the user when logging in to pin the session to the originating IP.
- Never include session information as part of a URL in order to support "cookieless" sessions. Rewrite URLs as form POSTs including the session identifier as a hidden field, instead.
- Provide a configurable option for automatically changing the session identifier transparently during a session: never, after a set time period, or a set number of requests.
Custom Framework Solution
Custom Code Solution