-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gentoo Linux Security Advisory GLSA 201401-08 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - http://security.gentoo.org/ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Severity: Normal Title: NTP: Traffic amplification Date: January 16, 2014 Bugs: #496776 ID: 201401-08 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Synopsis ======== NTP can be abused to amplify Denial of Service attack traffic. Background ========== NTP is a protocol designed to synchronize the clocks of computers over a network. The net-misc/ntp package contains the official reference implementation by the NTP Project. Affected packages ================= ------------------------------------------------------------------- Package / Vulnerable / Unaffected ------------------------------------------------------------------- 1 net-misc/ntp < 4.2.6_p5-r10 >= 4.2.6_p5-r10 Description =========== ntpd is susceptible to a reflected Denial of Service attack. Please review the CVE identifiers and references below for details. Impact ====== An unauthenticated remote attacker may conduct a distributed reflective Denial of Service attack on another user via a vulnerable NTP server. Workaround ========== We modified the default ntp configuration in =net-misc/ntp-4.2.6_p5-r10 and added "noquery" to the default restriction which disallows anyone to query the ntpd status, including "monlist". If you use a non-default configuration, and provide a ntp service to untrusted networks, we highly recommend you to revise your configuration to disable mode 6 and 7 queries for any untrusted (public) network. You can always enable these queries for specific trusted networks. For more details please see the "Access Control Support" chapter in the ntp.conf(5) man page. Resolution ========== All NTP users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose ">=net-misc/ntp-4.2.6_p5-r10" Note that the updated package contains a modified default configuration only. You may need to modify your configuration further. References ========== [ 1 ] CVE-2013-5211 http://nvd.nist.gov/nvd.cfm?cvename=CVE-2013-5211 [ 2 ] VU#348126 http://www.kb.cert.org/vuls/id/348126 Availability ============ This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-201401-08.xml Concerns? ========= Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users' machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org. License ======= Copyright 2014 Gentoo Foundation, Inc; referenced text belongs to its owner(s). The contents of this document are licensed under the Creative Commons - Attribution / Share Alike license. http://creativecommons.org/licenses/by-sa/2.5 -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJS2GxTAAoJEByNLmvcM7DulIwQAIOYyqCmbK80HgcscXBIk1Ff /mqRuc7EkW7o6+AgTSqp71+oV6pKrQ0rdrj44P8ZtnjLmpXnb5ZQO6VUv7+Bzaqu kEeP8gSvjwCqIFeqgpYcDmefpaLdd4SkZluECf4ZNyHdclSQ3tLduE5idAwTrMgw FE5lX2ZdfIPHrJBQXZ0PD4EFA+biwwD/nWBzuJj01DDcII1ULUDJQhEPRP3prM8a U6asQugmgky/ZqarpymPcldMYUCpwT6PjrvOh1NWPOv5dEscTKEIspSdfelPbLdA irSM7Z5AOWLDEk/D99jI346mE0Y+YYRoD7ZHqnuVWUZMa8WQ80+B6njYa5+0yRzx zkq2GouNP6rDJm+sJjYk66RXrn8gwBvq/PYcM1E1qRvjHknU8xlWLLzwhUPefJmO 8uPjnRXa9/ZXBKXCFPN9TcdfqOfmsCCVnIIoZ2k8NCMHfbc/U5yhYxT7MWK9cOOb 2j1elsSA40V65mzyWDU3GwinM8+gG3goCWVOEV9daCvovTbPrGXhGV8OPoDqOoCW jP7YQSeqx0mlEn7OrIhDsf3h7C8nblCMhZ0ahCgZ997VwXVj1Ngg25DoBN2LmG4H 4KpnRDdjXm4tpVF0vP90X83VY9PaamlBRI8gzZgt2wdYJPhJ1bCf1WRhctK1ywBP O7T3P0kq5BpFv/GVWOU1 =rXbW -----END PGP SIGNATURE-----