CVE-2022-24781 is a session fixation vulnerability (CWE-384) affecting versions of the math-geon project 'Geon' prior to 1.1.0. Geon is an educational board game centered around solving problems related to the Pythagorean Theorem. The vulnerability arises because the application allows malicious users to obtain the universally unique identifier (UUID) of other users' sessions and then spoof that UUID via the browser console. By doing so, an attacker can effectively become a co-owner of the victim's session. This means the attacker can hijack or share the session context, potentially gaining unauthorized access to the victim's game state or any associated data within that session. The vulnerability is rooted in improper session management where the UUID is not sufficiently protected or regenerated upon authentication, allowing session fixation attacks. The issue was addressed and patched in version 1.1.0 of Geon. There are no known workarounds for affected versions, and no known exploits have been reported in the wild to date. The attack requires the attacker to have some level of interaction with the victim, such as obtaining the UUID, which may be exposed through client-side mechanisms or insufficient access controls. The vulnerability impacts confidentiality and integrity of session data but does not directly affect availability. Since the vulnerability involves client-side manipulation and session management flaws, it can be exploited without elevated privileges but does require user interaction or social engineering to obtain the UUID from the victim.

For European organizations using Geon, particularly educational institutions or platforms integrating this game for learning purposes, this vulnerability could lead to unauthorized access to user sessions. Attackers could manipulate game states, potentially disrupting educational activities or compromising user data associated with sessions. While the direct impact on critical infrastructure or sensitive data is limited due to the nature of the application, the breach of session integrity undermines user trust and could be leveraged as a foothold for further attacks if Geon is integrated into larger platforms. Additionally, session fixation could allow attackers to impersonate users, leading to potential privacy violations under GDPR regulations. The impact is more pronounced in environments where Geon is used in multi-user or collaborative settings, increasing the risk of data leakage or manipulation. Since no known exploits are in the wild, the immediate risk is moderate, but unpatched deployments remain vulnerable to targeted attacks.

The primary mitigation is to upgrade all affected Geon instances to version 1.1.0 or later, where the session fixation vulnerability has been patched. Organizations should enforce strict session management policies, including regenerating session identifiers upon authentication and ensuring UUIDs are not exposed or guessable via client-side scripts or browser consoles. Implementing secure cookie flags (HttpOnly, Secure, SameSite) can reduce the risk of session hijacking. Additionally, monitoring for unusual session activity or multiple concurrent accesses from different clients sharing the same session UUID can help detect exploitation attempts. Educating users about the risks of sharing session identifiers and limiting browser console access can also reduce attack vectors. For organizations integrating Geon into broader platforms, isolating the game session context and applying additional authentication checks can further mitigate risks. Since no workaround exists for affected versions, patching remains the most effective defense.