apache2 vulnerabilities

USN-3627-1 fixed vulnerabilities in Apache HTTP Server. This update
provides the corresponding updates for Ubuntu 18.04 LTS.

Original advisory details:

Alex Nichols and Jakob Hirsch discovered that the Apache HTTP Server
mod_authnz_ldap module incorrectly handled missing charset encoding
headers. A remote attacker could possibly use this issue to cause the
server to crash, resulting in a denial of service. (CVE-2017-15710)

Elar Lang discovered that the Apache HTTP Server incorrectly handled
certain characters specified in <FilesMatch>. A remote attacker could
possibly use this issue to upload certain files, contrary to expectations.
(CVE-2017-15715)

It was discovered that the Apache HTTP Server mod_session module
incorrectly handled certain headers. A remote attacker could possibly use
this issue to influence session data. (CVE-2018-1283)

Robert Swiecki discovered that the Apache HTTP Server incorrectly handled
certain requests. A remote attacker could possibly use this issue to cause
the server to crash, leading to a denial of service. (CVE-2018-1301)

Robert Swiecki discovered that the Apache HTTP Server mod_cache_socache
module incorrectly handled certain headers. A remote attacker could
possibly use this issue to cause the server to crash, leading to a denial
of service. (CVE-2018-1303)

Nicolas Daniels discovered that the Apache HTTP Server incorrectly
generated the nonce when creating HTTP Digest authentication challenges.
A remote attacker could possibly use this issue to replay HTTP requests
across a cluster of servers. (CVE-2018-1312)