CVE-2025-57994 is an authorization bypass vulnerability classified under CWE-639 (Authorization Bypass Through User-Controlled Key) affecting the Sayful Islam Upcoming Events Lists product, up to version 1.4.0. This vulnerability arises from incorrectly configured access control mechanisms that allow an attacker with limited privileges (PR:L - privileges required) to manipulate user-controlled keys to bypass authorization checks. The vulnerability is remotely exploitable (AV:N - network attack vector) without requiring user interaction (UI:N), and it affects the integrity and availability of the system (I:L/A:L) but not confidentiality. The flaw allows an attacker to perform unauthorized actions or access restricted functionalities by exploiting the improper validation of access control levels tied to user-supplied keys. Although no known exploits are currently reported in the wild and no patches have been linked yet, the vulnerability's medium CVSS score of 5.4 reflects a moderate risk due to the ease of exploitation and potential impact on system integrity and availability. The vulnerability could enable attackers to disrupt event listings or manipulate event data, potentially causing operational disruptions or misinformation in environments relying on this software for event management.

For European organizations using the Sayful Islam Upcoming Events Lists software, this vulnerability could lead to unauthorized modification or disruption of event-related data, impacting business operations, event scheduling, and communication. Organizations in sectors such as education, public administration, cultural institutions, and event management that rely on this software for scheduling and public event dissemination could face operational challenges and reputational damage. The integrity loss could cause incorrect event information to be displayed or critical event data to be altered or deleted, while availability impact could result in denial of service for event listings. Although confidentiality is not directly impacted, the disruption of event data could indirectly affect organizational workflows and stakeholder trust. The requirement for some level of privileges to exploit the vulnerability means insider threats or compromised accounts could be leveraged by attackers. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially if attackers develop exploit code in the future.

European organizations should implement the following specific mitigation steps: 1) Conduct an immediate audit of access control configurations within the Upcoming Events Lists software to identify and correct any improper authorization logic related to user-controlled keys. 2) Restrict privileges to only trusted users and enforce the principle of least privilege to minimize the risk of exploitation by low-privileged accounts. 3) Monitor logs and event data for unusual access patterns or unauthorized modifications indicative of exploitation attempts. 4) Engage with the vendor or community maintaining the software to obtain patches or updates addressing this vulnerability as soon as they become available. 5) If patching is not immediately possible, implement compensating controls such as web application firewalls (WAFs) with custom rules to detect and block suspicious requests manipulating authorization keys. 6) Educate administrators and users about the risk of privilege misuse and enforce strong authentication mechanisms to reduce the likelihood of account compromise. 7) Regularly review and update access control policies to ensure they align with security best practices and mitigate risks from user-controlled input.