CVE-2023-23923 Moodle: possible to set the preferred "start page" of other users

What is CVE-2023-23923?

CVE-2023-23923 is a high-severity missing authorization vulnerability in Moodle Moodle, published on 17 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The vulnerability was found Moodle which exists due to insufficient limitations on the "start page" preference. A remote attacker can set that preference for another user. The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

Weakness: CWE-284

Which versions are affected by CVE-2023-23923?

9 open source packages ship an affected version, including moodle/moodle and moodle. It affects 1 product.

Products include Moodle Moodle.

How do I fix CVE-2023-23923?

Upgrade moodle/moodle to a fixed version for your release line: 3.9.19, 3.11.12, 4.0.6 or 4.1.1.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2023-23923 being exploited?

There is no known exploitation of CVE-2023-23923 in the wild and no public exploit code.

Other vulnerabilities in Moodle Moodle

• CVE-2006-4935 File upload in n/a Critical 10.0
• CVE-2006-4936 Moodle does not properly validate module instance id Critical 10.0
• CVE-2004-2233 Unknown "front page vulnerability with Moodle servers" for Moodle before 1.3.2 has unknown impact and attack vectors. Critical 10.0
• CVE-2004-2235 Cross-site scripting in n/a Critical 10.0
• CVE-2004-2236 Other in n/a Critical 10.0

All Moodle Moodle vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-moodle-2023-23923, GHSA-32jc-9p58-p82x, UBUNTU-CVE-2023-23923.