APR-util versions 1.6.3 (and earlier) function apr_password_validate() was not constant-time with regards to hashes or passwords comparisons, potentially leaking their content via a side channel timing attack particularly on platforms without crypt() such as  Windows, BeOS, NetWare, or Android. Users are recommended to upgrade to version 1.6.4, which fixes this issue.

A bug in APR-util version 1.6.3 (and earlier) allows a stack recursion attack against any library consumer which parses XML from untrusted sources and uses the apr_xml_quote_elem() function. Users are recommended to upgrade to version 1.6.4, which fixes this issue.

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in Apache Portable Runtime Utility via apr_dbd_oracle provider. This issue affects Apache Portable Runtime Utility: from 1.6.0 through 1.6.3

Heap-based Buffer Overflow vulnerability in Apache Portable Runtime Utility redis client. This issue affects Apache Portable Runtime Utility: from 1.6.0 through 1.6.3. Users are recommended to upgrade to version 1.6.4, which fixes the issue.

Heap-based Buffer Overflow vulnerability in Apache Portable Runtime Utility memcached client This issue affects Apache Portable Runtime Utility: from 1.3.0 through 1.6.3.