Moodle Quiz Override Screen cross site scripting

CVSS Meta Temp Score
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Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.4$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Moodle. This affects an unknown part of the component Quiz Override Screen. The manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2021-36399. It is possible to initiate the attack remotely. There is no exploit available. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Detailsinfo

A vulnerability was found in Moodle (Learning Management Software) (affected version not known). It has been rated as problematic. Affected by this issue is some unknown functionality of the component Quiz Override Screen. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

In Moodle, ID numbers displayed in the quiz override screens required additional sanitizing to prevent a stored XSS risk.

The weakness was shared 03/07/2023. The advisory is available at moodle.org. This vulnerability is handled as CVE-2021-36399 since 07/12/2021. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/06/2025). This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-0921). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.4
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔍
ATT&CK: 🔍

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

07/12/2021 🔍
03/07/2023 +603 days 🔍
03/07/2023 +0 days 🔍
07/06/2025 +852 days 🔍

Sourcesinfo

Product: moodle.org

Advisory: moodle.org
Status: Confirmed

CVE: CVE-2021-36399 (🔍)
GCVE (CVE): GCVE-0-2021-36399
GCVE (VulDB): GCVE-100-222434
EUVD: 🔍

Entryinfo

Created: 03/07/2023 08:39 AM
Updated: 07/06/2025 02:15 PM
Changes: 03/07/2023 08:39 AM (37), 04/01/2023 07:46 AM (11), 07/06/2025 02:15 PM (16)
Complete: 🔍
Cache ID: 18:729:40

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