The canonicalize_username function in svnserve/cyrus_auth.c in Apache Subversion before 1.8.16 and 1.9.x before 1.9.4, when Cyrus SASL authentication is used, allows remote attackers to authenticate and bypass intended access restrictions via a realm string that is a prefix of an expected repository realm string. The req_check_access function in the mod_authz_svn module in the httpd server in Apache Subversion before 1.8.16 and 1.9.x before 1.9.4 allows remote authenticated users to cause a denial of service via a crafted header in a MOVE or COPY request, involving an authorization check