What Is Cookies Hacking (Session Hijacking)?
Cookies hacking, also known as session hijacking, is a type of cyber attack where an attacker intercepts or steals a user’s session cookie to gain unauthorized access to their account or sensitive information on a web application.
A session cookie is a small piece of data stored by a web browser that keeps track of a user’s session on a website, enabling the site to remember the user’s preferences, login information, and other settings.
Once the attacker obtains a valid session cookie, they can use it to impersonate the user, potentially gaining access to sensitive information or performing actions on the user’s behalf without their consent.
This is part of a series of articles about application security.
How Does Cookie Hijacking Work?
Session hijacking can be accomplished through various methods, such as:
- Packet sniffing: An attacker monitors unencrypted network traffic to capture session cookies being transmitted between a user’s computer and the web server.
- Cross-site scripting (XSS): The attacker exploits vulnerabilities in a web application to inject malicious scripts that steal session cookies from a user’s browser.
- Man-in-the-Middle (MitM) attacks: The attacker positions themselves between the user and the web server to intercept and manipulate communications, including capturing session cookies.
- Social engineering: The attacker tricks the user into revealing their session cookies through phishing or other deceptive techniques.
- Physical access: An attacker with direct access to a user’s device may be able to retrieve session cookies from the browser’s cache or by using malware.
Here’s an overview of how a cookie hijacking attack might work:
- Identify target and method: The attacker identifies a target website or web application and selects an appropriate method to capture the user’s session cookies.
- Obtain session cookie: The attacker uses the chosen method to steal the user’s session cookie. For example, in an XSS attack, the attacker exploits a vulnerability in the web application to inject malicious scripts that steal the cookie from the user’s browser.
- Impersonate the user: Once the attacker has obtained a valid session cookie, they can use it to impersonate the user on the target website or web application. By sending requests to the web server with the stolen session cookie, the attacker tricks the server into believing that they are the legitimate user.
- Access sensitive information or perform actions: With the stolen session cookie, the attacker can potentially access the user’s account, view sensitive information, or perform actions on the user’s behalf without their knowledge or consent.
What Are the Risks and Consequences of Cookies Hacking?
Cookies hacking poses various risks and consequences for both users and organizations, such as:
- Unauthorized access: An attacker with a hijacked session cookie can gain unauthorized access to a user’s account, potentially viewing, modifying, or deleting sensitive information.
- Identity theft: If an attacker gains access to personal information such as names, addresses, social security numbers, or financial data, they can use it for identity theft or other fraudulent activities.
- Financial loss: Attackers may use hijacked sessions to make unauthorized purchases, transfer funds, or access financial accounts, leading to financial losses for users or businesses.
- Reputation damage: Both individuals and organizations can suffer reputational damage due to session hijacking, as it may lead to the unauthorized disclosure of private or sensitive information or unauthorized actions being carried out on behalf of the victim.
- Loss of privacy: Session hijacking can result in the loss of privacy for users, as attackers may gain access to personal messages, browsing history, or other private data.
- Legal consequences: Organizations that fail to adequately protect user data or maintain proper security measures may face legal consequences, fines, or penalties due to data breaches or non-compliance with privacy regulations.
- Loss of productivity: Dealing with the aftermath of a session hijacking attack can be time-consuming and costly for both individuals and organizations, leading to lost productivity as they work to remediate the issue, recover lost data, or restore affected systems.
4 Ways to Protect Against Cookie Hacking
1. Use HTTPS
Using HTTPS is crucial for securing the connection between a user’s browser and a web server. When a website employs HTTPS, it encrypts all data transmitted between the client and the server, including session cookies, preventing attackers from eavesdropping or tampering with the data. HTTPS relies on SSL/TLS (Secure Sockets Layer/Transport Layer Security) certificates to establish a secure connection and validate the identity of the server.
In addition to protecting against session hijacking, HTTPS also helps build trust with users by providing visual cues in the browser (e.g., a padlock icon) that indicate a secure connection. Web developers should enforce HTTPS by default and use HSTS (HTTP Strict Transport Security) to ensure that browsers only connect to their site using secure connections.
2. Rely on Web Frameworks for Session Cookie Management
Web frameworks are software libraries designed to simplify web development tasks and often include built-in security features that help protect against session hijacking. By relying on these frameworks for session cookie management, developers can benefit from secure default settings, ongoing security updates, and community-supported best practices.
Features such as secure cookie flags, which ensure that cookies are only transmitted over HTTPS, and HttpOnly attributes, which prevent cookies from being accessed through client-side scripts, can help mitigate the risk of cookies hacking. Additionally, web frameworks often provide built-in mechanisms to protect against cross-site request forgery (CSRF) attacks, further enhancing the security of session cookies.
3. Change the Session Key After Authentication
Session fixation is a type of session hijacking attack where an attacker forces a user to use a specific session identifier that the attacker knows beforehand. To defend against session fixation, developers should change the session key or regenerate the session ID after a user has successfully authenticated.
By doing so, any previously known session key becomes invalid, preventing attackers from using it to gain unauthorized access to the user’s account. Implementing this security measure ensures that even if an attacker manages to set a session ID before authentication, they will not be able to hijack the user’s session after the user logs in.
4. Time Box User Sessions and Require Automatic Logoff
Setting time-based restrictions on user sessions can help reduce the risk of session hijacking by limiting the window of opportunity for attackers. By implementing session timeouts, developers can automatically log users out of their accounts after a specified period of inactivity.
This precaution forces potential attackers to act within a narrow time frame, making it more difficult for them to hijack a session successfully. Furthermore, developers can require users to re-authenticate periodically, even if they remain active on the site. This measure adds an extra layer of security by ensuring that only authenticated users can maintain access to sensitive information or functionality.
Application Protection with Imperva
Imperva provides a Web Application Firewall, which prevent attacks such as cookies hijacking with world-class analysis of web traffic to your applications.
Beyond cookies hijacking protection, Imperva provides comprehensive protection for applications, APIs, and microservices:
Runtime Application Self-Protection (RASP) – Real-time attack detection and prevention from your application runtime environment goes wherever your applications go. Stop external attacks and injections and reduce your vulnerability backlog.
API Security – Automated API protection ensures your API endpoints are protected as they are published, shielding your applications from exploitation.
Advanced Bot Protection – Prevent business logic attacks from all access points – websites, mobile apps and APIs. Gain seamless visibility and control over bot traffic to stop online fraud through account takeover or competitive price scraping.
DDoS Protection – Block attack traffic at the edge to ensure business continuity with guaranteed uptime and no performance impact. Secure your on premises or cloud-based assets – whether you’re hosted in AWS, Microsoft Azure, or Google Public Cloud.
Attack Analytics – Ensures complete visibility with machine learning and domain expertise across the application security stack to reveal patterns in the noise and detect application attacks, enabling you to isolate and prevent attack campaigns.
Client-Side Protection – Gain visibility and control over third-party JavaScript code to reduce the risk of supply chain fraud, prevent data breaches, and client-side attacks.
