CVE-2025-10493: 
WordPress vulnerability analysis and mitigation

The Chained Quiz plugin for WordPress contains an Insecure Direct Object Reference (IDOR) vulnerability (CVE-2025-10493) in version 1.3.4 and below. The vulnerability was discovered on September 17, 2025, affecting the quiz submission and completion mechanisms due to missing validation on a user-controlled key. This security flaw allows unauthenticated attackers to manipulate the chainedcompletionid cookie value (NVD).

The vulnerability stems from insufficient validation of the chainedcompletionid cookie in the quiz completion process. The CVSS v3.1 score is 5.3 (Medium) with a vector string of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N. The issue is classified as CWE-639 (Authorization Bypass Through User-Controlled Key). The vulnerability was partially addressed in versions 1.3.4 and 1.3.5, with a final fix implemented in version 1.3.6 to resolve a database query error (Wordfence).

The vulnerability enables unauthenticated attackers to hijack and modify other users' quiz attempts. Attackers can alter quiz answers, scores, and results of any user by manipulating the cookie value, potentially compromising the integrity of quiz submissions (NVD).

The vulnerability was addressed through multiple patches. Version 1.3.4 introduced initial fixes, followed by improvements in version 1.3.5, and a final fix for a database query error in version 1.3.6. Users should upgrade to the latest version to ensure complete protection (WordPress Plugin).