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

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

by Michael Hawkins -
Number of replies: 0

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