23 August 2018
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2018.2499 Resource exhaustion in IP fragment reassembly 23 August 2018 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: FreeBSD kernel Publisher: FreeBSD Operating System: FreeBSD Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2018-6923 Reference: ESB-2018.2417 ESB-2018.2296.2 Original Bulletin: http://www.vuxml.org/freebsd/359e1548-a652-11e8-805b-a4badb2f4699.html - --------------------------BEGIN INCLUDED TEXT-------------------- FreeBSD -- Resource exhaustion in IP fragment reassembly Affected packages 11.2 <= FreeBSD-kernel < 11.2_2 11.1 <= FreeBSD-kernel < 11.1_13 Details VuXML ID 359e1548-a652-11e8-805b-a4badb2f4699 Discovery 2018-08-14 Entry 2018-08-22 Problem Description: A researcher has notified us of a DoS attack applicable to another operating system. While FreeBSD may not be vulnerable to that exact attack, we have identified several places where inadequate DoS protection could allow an attacker to consume system resources. It is not necessary that the attacker be able to establish two-way communication to carry out these attacks. These attacks impact both IPv4 and IPv6 fragment reassembly. Impact: In the worst case, an attacker could send a stream of crafted fragments with a low packet rate which would consume a substantial amount of CPU. Other attack vectors allow an attacker to send a stream of crafted fragments which could consume a large amount of CPU or all available mbuf clusters on the system. These attacks could temporarily render a system unreachable through network interfaces or temporarily render a system unresponsive. The effects of the attack should clear within 60 seconds after the attack stops. References CVE Name CVE-2018-6923 FreeBSD Advisory SA-18:10.ip - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to firstname.lastname@example.org and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. 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On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBW34kw2aOgq3Tt24GAQg0jA//ULC3g5GFq4/tbtJBjz3F5Bkmti5jvxsM 9q+0IJkoiuCJ3+Y5EsgR8EFL+t+86R83FTegdvncPp/paxkYoufdgHIyqD73KdAi NcxzZDVPSoeZL8+ObfxRYcSt0qxs00f3y0r8voHUT9BfrUPCGpiFG9S9sdPsGmN4 dXzq/KOl+pqcz7/LFl5hSfn5Hn3SPVtMxJ11XBr+H/8EP1w2lEloMCcbcmwwmqYb ImjWLaVGNl7DkW/FIYaZGdiz1tQrGr7KBgkRgAkLxkWcij/NI7wx3kjVO9r4PeVM 3jfKxfln717h7VN/pxiEYHYhRm91akHrZNGEDNQ+Yyplgpbs706Hpfs90nzR7kZL V76UscGarCkk8NFTGhSdRDvI5VTRii6qa4Lp0a+07s0DxIErIlFUjKwz7rMvHT8Z wH6jP6BTVPwu4tbx7BlGFOJQPYZGqjDsoleG82wfT7e7050ey1eGi+AyJfOLpzFb reyOlmJbEkaTEdmWIsmeut5rh/JjcmMwO5fY69R9jCmq6JdgFUeoxG0rgv3N77n7 KTIKunzsDVy2LOj5mC1pw8MyGPj3V+eivzZnDPVQXMUA/Y6GxLjwrXwF47kIuNfG MJAebnDEBfS9QPI3niahWLQic0eZ1S+lMWlGs0aj78lHpytXMnD/yWkhrdOyWC5T rJFZv5BgJNA= =biic -----END PGP SIGNATURE-----