In the ever-evolving web security landscape, Session Fixation demands our attention. This article delves from a high-level overview to its technical depths, underlining its importance through a real-world case involving Schneider Electric's EcoStruxure™ Power Monitoring Expert (PME).

Session Fixation

Session Fixation is an attack that lets an unauthorized person take control of a valid user's session in a web application. This happens because of certain vulnerabilities in how web apps handle session IDs.

Essentially, session management is crucial in web apps as it helps track user interactions seamlessly. The problem arises in some web applications during user authentication when instead of creating a new session ID, these apps stick with the old one, leaving a gap.

To launch a Session Fixation attack, the attacker first needs a valid session ID, which they can obtain in various ways.

How to get valid session ID?

The one of the most method to gain valid session ID is Phishing Attacks, wherein attackers create fraudulent websites or emails that mimic legitimate web applications. Users are misled into revealing their session IDs.

Furthermore, some applications generate session IDs with insufficient randomness, making them predictable. Attackers can take advantage of this vulnerability to predict session IDs more easily, facilitating Session Fixation attacks.

Cross-Site Scripting (XSS) vulnerabilities in web applications offer attackers yet another avenue. Exploiting these vulnerabilities allows them to inject malicious scripts into the application, potentially enabling the theft of session IDs from other users. Moreover, in certain cases, the attacker can also force-set someone's cookie. If the application fails to change the cookie before a user logs in, this can lead to session hijacking.

Once the users have logged in, the attacker takes over the session, using their knowledge of the session ID.

Real-World Consequences

The consequences of Session Fixation reach far beyond the technical realm, impacting business operations and reputation. A successful attack can result in unauthorized access, data breaches, and the misuse of user accounts. This not only tarnishes an organization's reputation but also inflicts tangible financial losses and potential legal repercussions.

Now, turning our attention to a real-world case, the Schneider Electric's EcoStruxure™ Power Monitoring Expert (PME) product confronted a Session Fixation vulnerability. This specific vulnerability, identified as CVE-2023-28003, was uncovered by security researchers from A1 Digital Security Professional Services. It garnered a Common Vulnerability Scoring System (CVSS) score of 6.7, categorizing it as a medium-level threat.

This vulnerability introduced the potential for an attacker to maintain unauthorized access, even after a legitimate user had logged out of their account. Unauthorized access and control over essential infrastructure could lead to operational disruptions, safety compromises, and various substantial real-world consequences.

Details about the aforementioned vulnerability can be found in the Schneider Electric Cybersecurity support portal.