Chained Quiz 1.3.5 - Unauthenticated Insecure Direct Object Reference via Cookie
Chained Quiz 1.3.5 - Unauthenticated Insecure Direct Object Reference via Cookie
AI Analysis
Technical Summary
The Chained Quiz 1.3.5 application contains an Insecure Direct Object Reference (IDOR) vulnerability that can be exploited without authentication by manipulating cookie values. IDOR vulnerabilities occur when an application exposes references to internal implementation objects such as files, database records, or keys, without proper access control checks. In this case, the vulnerability allows an attacker to alter a cookie to gain unauthorized access to quiz data or administrative functions. Since the exploit does not require user authentication, it significantly lowers the barrier for attackers. The vulnerability stems from insufficient validation of cookie parameters, which the server trusts to identify and authorize user actions. The exploit code, although provided in a generic text format, demonstrates how an attacker can craft malicious cookies to bypass access controls. While no active exploitation has been observed in the wild, the presence of exploit code increases the risk of future attacks. The vulnerability affects web-based deployments of Chained Quiz 1.3.5, commonly used in educational and training environments. Without proper mitigation, attackers could view or modify sensitive quiz content, disrupt service availability, or compromise user data integrity. The lack of an official patch or update at the time of reporting necessitates immediate defensive measures such as input validation and access control enforcement at the application layer.
Potential Impact
For European organizations, particularly those in education and e-learning sectors, this vulnerability could lead to unauthorized disclosure of sensitive quiz content, manipulation of quiz results, and potential disruption of learning services. Confidentiality is at risk as attackers can access data without authentication. Integrity is compromised by the possibility of unauthorized modification of quiz data. Availability could be affected if attackers disrupt quiz functionality. The unauthenticated nature of the exploit increases the risk of widespread abuse, especially in institutions relying heavily on Chained Quiz for assessments. Data privacy regulations such as GDPR may also be implicated if personal data is exposed. The overall impact could damage organizational reputation, lead to regulatory penalties, and undermine trust in digital learning platforms.
Mitigation Recommendations
1. Immediately implement strict validation and sanitization of all cookie values on the server side to prevent unauthorized manipulation. 2. Enforce robust access control checks for all object references, ensuring that users can only access resources they are authorized to. 3. Monitor web server and application logs for unusual cookie values or access patterns indicative of exploitation attempts. 4. Restrict cookie scope and set secure flags (HttpOnly, Secure) to reduce the risk of interception or tampering. 5. If possible, disable or limit the use of cookies for sensitive object references until a patch is available. 6. Engage with the software vendor or community to obtain patches or updates addressing the vulnerability. 7. Conduct a thorough security review of the application’s session and authorization mechanisms. 8. Educate administrators and users about the risk and signs of exploitation to enable rapid response.
Affected Countries
Germany, France, United Kingdom, Netherlands, Sweden, Finland, Denmark
Indicators of Compromise
- exploit-code: # Exploit Title: Chained Quiz 1.3.5 - Unauthenticated Insecure Direct Object Reference via Cookie # Date: 19-12-2025 # Exploit Author: Karuppiah Sabari Kumar(0xsabre) # Vendor Homepage: https://wordpress.org/plugins/chained-quiz/ # Software Link: https://downloads.wordpress.org/plugin/chained-quiz.1.3.3.zip # Version: <= 1.3.3 # Tested on: WordPress / Linux # CVE: CVE-2025-10493 ------------------------------------------------------------ ## Vulnerability Type Insecure Direct Object Reference (IDOR) / Improper Authorization ------------------------------------------------------------ ## Description The Chained Quiz plugin stores each quiz attempt using a predictable, auto-incrementing database ID (completion_id) and exposes this value directly in a client-side cookie named: chained_completion_id<quiz_id> When submitting or re-submitting quiz answers via admin-ajax.php, the server updates the quiz attempt record based solely on this cookie value, without verifying that the attempt belongs to the currently authenticated user. No authentication is required to exploit this vulnerability when the plugin is used with default settings. The server retrieves the quiz attempt directly using the completion_id from the cookie and performs an UPDATE query without verifying ownership. As a result, an attacker can hijack or tamper with other users’ quiz attempts by guessing or enumerating valid completion_id values and replaying answer submissions. ------------------------------------------------------------ ## Affected Component Quiz submission and results handling functionality via admin-ajax.php ------------------------------------------------------------ ## Proof of Concept (PoC) ### Step 1: Victim user submission A user completes a quiz. The submission is stored using a completion ID and associated with the user’s session via a cookie, for example: chained_completion_id1=2 ------------------------------------------------------------ ### Step 2: Attacker interception The attacker completes the same quiz and intercepts their own submission request using a proxy or browser developer tools. Example request: POST /wp-admin/admin-ajax.php HTTP/1.1 Host: localhost Cookie: chained_completion_id1=1 Connection: keep-alive Content-Type: application/x-www-form-urlencoded answer=0&question_id=1&quiz_id=1&post_id=117&question_type=radio&points=0&action=chainedquiz_ajax&chainedquiz_action=answer&total_questions=1 ------------------------------------------------------------ ### Step 3: Tampering The attacker modifies the cookie value to match another user’s quiz attempt, for example: chained_completion_id1=2 The attacker may also modify parameters such as "answer" or "points" to manipulate quiz responses or scores. The modified request is then sent to the server. ------------------------------------------------------------ ### Step 4: Result The server overwrites the victim user’s quiz submission, including answers and points, without validating ownership of the completion ID. ------------------------------------------------------------ ## Impact An attacker can arbitrarily modify quiz answers, scores, or results belonging to other users. This results in an integrity violation of quiz data and allows unauthorized manipulation of finalized quiz attempts. In environments where quiz results are used for assessments, leaderboards, or certificates, this can undermine trust in the platform and affect any downstream integrations that rely on quiz completion data. ------------------------------------------------------------ ## CWE - CWE-639: Authorization Bypass Through User-Controlled Key - CWE-285: Improper Authorization ------------------------------------------------------------
Chained Quiz 1.3.5 - Unauthenticated Insecure Direct Object Reference via Cookie
Description
Chained Quiz 1.3.5 - Unauthenticated Insecure Direct Object Reference via Cookie
AI-Powered Analysis
Technical Analysis
The Chained Quiz 1.3.5 application contains an Insecure Direct Object Reference (IDOR) vulnerability that can be exploited without authentication by manipulating cookie values. IDOR vulnerabilities occur when an application exposes references to internal implementation objects such as files, database records, or keys, without proper access control checks. In this case, the vulnerability allows an attacker to alter a cookie to gain unauthorized access to quiz data or administrative functions. Since the exploit does not require user authentication, it significantly lowers the barrier for attackers. The vulnerability stems from insufficient validation of cookie parameters, which the server trusts to identify and authorize user actions. The exploit code, although provided in a generic text format, demonstrates how an attacker can craft malicious cookies to bypass access controls. While no active exploitation has been observed in the wild, the presence of exploit code increases the risk of future attacks. The vulnerability affects web-based deployments of Chained Quiz 1.3.5, commonly used in educational and training environments. Without proper mitigation, attackers could view or modify sensitive quiz content, disrupt service availability, or compromise user data integrity. The lack of an official patch or update at the time of reporting necessitates immediate defensive measures such as input validation and access control enforcement at the application layer.
Potential Impact
For European organizations, particularly those in education and e-learning sectors, this vulnerability could lead to unauthorized disclosure of sensitive quiz content, manipulation of quiz results, and potential disruption of learning services. Confidentiality is at risk as attackers can access data without authentication. Integrity is compromised by the possibility of unauthorized modification of quiz data. Availability could be affected if attackers disrupt quiz functionality. The unauthenticated nature of the exploit increases the risk of widespread abuse, especially in institutions relying heavily on Chained Quiz for assessments. Data privacy regulations such as GDPR may also be implicated if personal data is exposed. The overall impact could damage organizational reputation, lead to regulatory penalties, and undermine trust in digital learning platforms.
Mitigation Recommendations
1. Immediately implement strict validation and sanitization of all cookie values on the server side to prevent unauthorized manipulation. 2. Enforce robust access control checks for all object references, ensuring that users can only access resources they are authorized to. 3. Monitor web server and application logs for unusual cookie values or access patterns indicative of exploitation attempts. 4. Restrict cookie scope and set secure flags (HttpOnly, Secure) to reduce the risk of interception or tampering. 5. If possible, disable or limit the use of cookies for sensitive object references until a patch is available. 6. Engage with the software vendor or community to obtain patches or updates addressing the vulnerability. 7. Conduct a thorough security review of the application’s session and authorization mechanisms. 8. Educate administrators and users about the risk and signs of exploitation to enable rapid response.
Affected Countries
Technical Details
- Edb Id
- 52464
- Has Exploit Code
- true
- Code Language
- text
Indicators of Compromise
Exploit Source Code
Exploit code for Chained Quiz 1.3.5 - Unauthenticated Insecure Direct Object Reference via Cookie
# Exploit Title: Chained Quiz 1.3.5 - Unauthenticated Insecure Direct Object Reference via Cookie # Date: 19-12-2025 # Exploit Author: Karuppiah Sabari Kumar(0xsabre) # Vendor Homepage: https://wordpress.org/plugins/chained-quiz/ # Software Link: https://downloads.wordpress.org/plugin/chained-quiz.1.3.3.zip # Version: <= 1.3.3 # Tested on: WordPress / Linux # CVE: CVE-2025-10493 ------------------------------------------------------------ ## Vulnerability Type Insecure Direct Object Reference... (3262 more characters)
Threat ID: 694d89022ffa995e0c012b32
Added to database: 12/25/2025, 6:57:06 PM
Last enriched: 1/17/2026, 8:03:58 AM
Last updated: 2/7/2026, 11:34:41 AM
Views: 93
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Related Threats
Concerns Raised Over CISA’s Silent Ransomware Updates in KEV Catalog
MediumSIEM Rules for detecting exploitation of vulnerabilities in FortiCloud SSO
MediumResearchers Expose Network of 150 Cloned Law Firm Websites in AI-Powered Scam Campaign
MediumItaly Averted Russian-Linked Cyberattacks Targeting Winter Olympics Websites, Foreign Minister Says
MediumChina-Linked Amaranth-Dragon Exploits WinRAR Flaw in Espionage Campaigns
MediumActions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console in Console -> Billing for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.