X-Forwarded-For headers could be used to spoof a user's IP, in order to bypass remote address checks.
PATCH NOTE: For user IPs to be checked (and logged) accurately after this patch is applied, sites using multiple levels of reverse proxies/balancers that append to the X-Forwarded-For header will need to configure the new "reverseproxyignore" setting. This ensures the IPs of the later proxies are ignored in favour of the user's IP.
| Severity/Risk: | Serious |
| Versions affected: | 3.8 to 3.8.1, 3.7 to 3.7.4, 3.6 to 3.6.8, 3.5 to 3.5.10 and earlier unsupported versions |
| Versions fixed: | 3.8.2, 3.7.5, 3.6.9 and 3.5.11 |
| Reported by: | Brendan Heywood |
| CVE identifier: | CVE-2020-1755 |
| Changes (master): | http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-67861 |
| Tracker issue: | MDL-67861 IP addresses can be spoofed using X-Forwarded-For |