The Fuzzing Project reports:
Apache httpd allows remote attackers to read secret data from
process memory if the Limit directive can be set in a user's
.htaccess file, or if httpd.conf has certain misconfigurations,
aka Optionsbleed. This affects the Apache HTTP Server through
2.2.34 and 2.4.x through 2.4.27. The attacker sends an
unauthenticated OPTIONS HTTP request when attempting to read
secret data. This is a use-after-free issue and thus secret data
is not always sent, and the specific data depends on many factors
including configuration. Exploitation with .htaccess can be
blocked with a patch to the ap_limit_section function in
server/core.c.