MSA-20-0003: IP addresses can be spoofed using X-Forwarded-For

by Michael Hawkins.  

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

Read more https://moodle.org/mod/forum/discuss.php?d=398351&parent=1606855