It was found that the FtpClient implementation in the Networking component of OpenJDK did not set connect and read timeouts by default. A malicious FTP server or a man-in-the-middle attacker could use this flaw to block execution of a Java application connecting to an FTP server.
Oracle JDK release notes include the following note regarding this fix: core-libs/java.net Default timeouts have changed for FTP URL handler Timeouts used by the FTP URL protocol handler have been changed from infinite to 5 minutes. This will result in an IOException from connect and read operations if the FTP server is unresponsive. For example, new URL("ftp://example.com").openStream().read(), will fail with java.net.SocketTimeoutException in case a connection or reading could not be completed within 5 minutes. To revert this behaviour to that of previous releases, the following system properties may be used, sun.net.client.defaultReadTimeout=0, sun.net.client.defaultConnectTimeout=0 JDK-8181612 (not public) http://www.oracle.com/technetwork/java/javase/9-0-1-relnotes-3883752.html http://www.oracle.com/technetwork/java/javase/8u151-relnotes-3850493.html http://www.oracle.com/technetwork/java/javaseproducts/documentation/javase7supportreleasenotes-1601161.html#R170_161 http://www.oracle.com/technetwork/java/javase/documentation/overview-156328.html#R160_171
Public now via Oracle CPU October 2017: http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html#AppendixJAVA The issue was fixed in Oracle JDK 9.0.1, 8u151, 7u161, and 6u171.
OpenJDK-8 upstream commit: http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/rev/84b0fbbfb8d6
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Via RHSA-2017:2998 https://access.redhat.com/errata/RHSA-2017:2998
This issue has been addressed in the following products: Oracle Java for Red Hat Enterprise Linux 6 Oracle Java for Red Hat Enterprise Linux 7 Via RHSA-2017:2999 https://access.redhat.com/errata/RHSA-2017:2999
This issue has been addressed in the following products: Oracle Java for Red Hat Enterprise Linux 6 Oracle Java for Red Hat Enterprise Linux 7 Via RHSA-2017:3047 https://access.redhat.com/errata/RHSA-2017:3047
This issue has been addressed in the following products: Oracle Java for Red Hat Enterprise Linux 7 Oracle Java for Red Hat Enterprise Linux 6 Via RHSA-2017:3046 https://access.redhat.com/errata/RHSA-2017:3046
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Supplementary Via RHSA-2017:3264 https://access.redhat.com/errata/RHSA-2017:3264
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Supplementary Via RHSA-2017:3267 https://access.redhat.com/errata/RHSA-2017:3267
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Supplementary Red Hat Enterprise Linux 7 Supplementary Via RHSA-2017:3268 https://access.redhat.com/errata/RHSA-2017:3268
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Via RHSA-2017:3392 https://access.redhat.com/errata/RHSA-2017:3392
This issue has been addressed in the following products: Red Hat Satellite 5.8 Red Hat Satellite 5.8 ELS Via RHSA-2017:3453 https://access.redhat.com/errata/RHSA-2017:3453