Incorrect domain matching logic made it possible to bypass the proxy, which could result in access to hosts intended to be blocked by the proxy.
| Severity/Risk: | Serious |
| Versions affected: | 4.2 to 4.2.1, 4.1 to 4.1.4, 4.0 to 4.0.9, 3.11 to 3.11.15, 3.9 to 3.9.22 and earlier unsupported versions |
| Versions fixed: | 4.2.2, 4.1.5, 4.0.10, 3.11.16 and 3.9.23 |
| Reported by: | Brendan Heywood |
| Workaround: | Add hosts blocked within the proxy to the Moodle cURL blocked hosts configuration if possible, until the patch is applied. |
| CVE identifier: | CVE-2023-40316 |
| Changes (master): | http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-74289 |
| Tracker issue: | MDL-74289 Proxy bypass risk due to insufficient validation |