CVE-2019-3809 : Exploit Details and Defense Strategies

A vulnerability has been discovered in Moodle versions 3.1 to 3.1.15 and earlier unsupported versions, allowing for potential blind SSRF attacks.

Understanding CVE-2019-3809

This CVE affects Moodle versions 3.1 to 3.1.15 and earlier unsupported versions due to a flaw in the mybackpack feature.

What is CVE-2019-3809?

This vulnerability in Moodle versions 3.1 to 3.1.15 and earlier unsupported versions stems from unrestricted setting of the URL for badges, enabling blind SSRF attacks.

The Impact of CVE-2019-3809

The vulnerability allows attackers to initiate blind SSRF attacks through requests made by the page, potentially leading to unauthorized access and data leakage.

Technical Details of CVE-2019-3809

This section delves into the technical aspects of the CVE.

Vulnerability Description

The flaw in Moodle versions 3.1 to 3.1.15 and earlier unsupported versions lies in the mybackpack feature, which permits unrestricted setting of badge URLs, opening the door to blind SSRF attacks.

Affected Systems and Versions

Product: Moodle
Vendor: [UNKNOWN]
Versions Affected: 3.1.16

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: None
User Interaction: None
Scope: Unchanged
CVSS Base Score: 6.5 (Medium)

Mitigation and Prevention

Protecting systems from CVE-2019-3809 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Moodle to version 3.1.16 to mitigate the vulnerability.
Monitor and restrict URL settings to prevent unauthorized access.

Long-Term Security Practices

Regularly update Moodle to the latest versions to patch known vulnerabilities.
Implement network controls to restrict outbound requests and prevent SSRF attacks.

Patching and Updates

Apply patches provided by Moodle to address the vulnerability and enhance system security.