Chiwopsezo chakutali cha DoS mu FreeBSD IPv6 stack

Pa FreeBSD kuthetsedwa chiopsezo (CVE-2019-5611) chomwe chimakupatsani mwayi woyambitsa kuwonongeka kwa kernel (packet-of-death) potumiza mapaketi ogawanika a ICMPv6 MLD (Multicast Listener Discovery). Vuto zidayambitsa kusowa kwa cheke chofunikira mu foni ya m_pulldown (), zomwe zingapangitse kuti mambuf osalumikizana abwezedwe, mosiyana ndi zomwe woyimbayo amayembekeza.

Chiwopsezo kuthetsedwa mu zosintha 12.0-KUTULUKA-p10, 11.3-KUTULUKA-p3 ndi 11.2-KUTULUKA-p14. Monga njira yoyendetsera chitetezo, mutha kuletsa chithandizo chogawikana cha IPv6 kapena zosankha zamutu zosefera pa firewall. HBH (Hop-by-Hop). Chosangalatsa ndichakuti, cholakwika chomwe chimatsogolera pachiwopsezo chidadziwika kale mu 2006 ndikukhazikika ku OpenBSD, NetBSD ndi macOS, koma sichinakhazikike mu FreeBSD, ngakhale opanga FreeBSD adadziwitsidwa za vutoli.

Mutha kuzindikiranso kuchotsedwa kwa zovuta zina ziwiri mu FreeBSD:

• CVE-2019-5603 - Kusefukira kwa kauntala yolozera kuzinthu za data mumzere mukamagwiritsa ntchito malaibulale a 32-bit pamalo a 64-bit (32-bit compat). Vuto limapezeka pamene kuloleza mqueuefs, amene si yogwira ndi kusakhulupirika, ndipo zingachititse kupeza owona, akalozera ndi sockets anatsegula ndi njira za owerenga ena, kapena kupeza owona kunja kwa ndende chilengedwe. Ngati wogwiritsa ntchito ali ndi mizu yolowera kundende, kusatetezekako kumalola munthu kupeza mizu kumbali ya malo omwe akukhalamo.
• CVE-2019-5612 - vuto lokhala ndi milu yambiri yofikira pa chipangizo cha /dev/midistat pomwe mtundu wamtundu umachitika kungayambitse kuwerengera madera a kernel memory kunja kwa malire a buffer yoperekedwa kwa midistat. Pamakina a 32-bit, kuyesa kugwiritsa ntchito chiwopsezo kumabweretsa kuwonongeka kwa kernel, ndipo pamakina a 64-bit amalola munthu kudziwa zomwe zili m'malo osasinthika a kernel memory.

Source: opennet.ru