Ts'ebetso ea DDIO ho li-chips tsa Intel e lumella tlhaselo ea marang-rang ho bona li-keytroke nakong ea SSH

Sehlopha sa bafuputsi ba Vrije Universiteit Amsterdam le ETH Zurich ba thehile mokhoa oa ho hlasela marang-rang. NetCAT (Network Cache ATtack), e lumellang, ho sebelisa mekhoa ea ho hlahloba lintlha ka liteishene tsa batho ba bang, ho fumana ka thōko linotlolo tse hatelitsoeng ke mosebedisi ha u ntse u sebetsa sebokeng sa SSH. Bothata bo hlaha feela ho li-server tse sebelisang theknoloji RDMA ( phihlello ya memori e hole) le DDIO (Data-Direct I/O).

Intel nahana, hore tlhaselo e thata ho kenya ts'ebetsong ts'ebetsong, kaha e hloka ho fihlella ha mohlaseli ho marang-rang a sebaka seo, maemo a nyopa le mokhatlo oa puisano ea moeti o sebelisa theknoloji ea RDMA le DDIO, e atisang ho sebelisoa marang-rang a ka thōko, mohlala, moo computing. lihlopha li sebetsa. Taba e lekantsoe Nyenyane (CVSS 2.6, CVE-2019-11184) 'me ho fanoe ka khothaletso ea hore DDIO le RDMA li se ke tsa lumella marang-rang a lehae moo sebaka sa ts'ireletso se sa fanoang le khokahano ea bareki ba sa tšepahaleng e lumelletsoeng. DDIO esale e sebelisoa ho li-processor tsa Intel ho tloha 2012 (Intel Xeon E5, E7 le SP). Litsamaiso tse thehiloeng ho li-processor tse tsoang ho AMD le bahlahisi ba bang ha li amehe ke bothata, kaha ha li tšehetse ho boloka data e fetisitsoeng holim'a marang-rang ho cache ea CPU.

Mokhoa o sebelisoang bakeng sa tlhaselo o tšoana le ho ba kotsing "Sehlapi", e u lumellang hore u fetole litaba tsa li-bits tsa RAM ka ho qhekella lipakete tsa marang-rang ka har'a litsamaiso tse nang le RDMA. Bothata bo bocha ke phello ea mosebetsi oa ho fokotsa tieho ha u sebelisa mochine oa DDIO, o netefatsang ho sebelisana ka ho toba ha karete ea marang-rang le lisebelisoa tse ling tsa peripheral le cache ea processor (ha ho ntse ho etsoa lipakete tsa karete ea marang-rang, data e bolokiloe ka har'a cache le ho kenya letsoho ka ho toba ka har'a lipakete tsa marang-rang. e ntshitswe ho cache, ntle le ho fihlella memori).

Ka lebaka la DDIO, cache ea processor e boetse e kenyelletsa data e hlahisitsoeng nakong ea ts'ebetso e mpe ea marang-rang. Tlhaselo ea NetCAT e ipapisitse le taba ea hore likarete tsa marang-rang li boloka data ka mafolofolo, 'me lebelo la ts'ebetso ea lipakete ho marang-rang a sejoale-joale a lehae le lekane ho susumetsa ho tlatsoa ha cache le ho tseba boteng kapa ho ba sieo ha data ka har'a cache ka ho sekaseka tieho nakong ea data. phetiso.

Ha u sebelisa linako tse kopanetsoeng, tse kang ka SSH, pakete ea marang-rang e romelloa hang ka mor'a hore senotlolo se hatisoe, ke hore. tieho lipakeng tsa lipakete tse tsamaellanang le tieho lipakeng tsa likonopo. Ho sebelisa mekhoa ea ho hlahloba lipalo-palo le ho ela hloko hore tieho lipakeng tsa linotlolo hangata e itšetlehile ka boemo ba senotlolo ho keyboard, hoa khoneha ho tsosolosa boitsebiso bo kentsoeng ka monyetla o itseng. Mohlala, batho ba bangata ba tloaetse ho ngola "s" kamora "a" kapele ho feta "g" kamora "s".

Lintlha tse kentsoeng ka har'a cache ea processor li boetse li lumella motho ho ahlola nako e nepahetseng ea lipakete tse rometsoeng ke karete ea marang-rang ha a sebetsana le likhokahano tse kang SSH. Ka ho hlahisa phallo e itseng ea sephethephethe, mohlaseli a ka tseba nako eo data e ncha e hlahang ka har'a cache e amanang le mosebetsi o itseng oa sistimi. Ho sekaseka litaba tsa cache, mokhoa ona o sebelisoa Prime+Probe, e kenyelletsang ho tlatsa cache ka lethathamo la litšupiso tsa boleng le ho lekanya nako ea phihlello ho tsona ha li fetisetsoa ho bona liphetoho.

Ts'ebetso ea DDIO ho li-chips tsa Intel e lumella tlhaselo ea marang-rang ho bona li-keytroke nakong ea SSH

Ho ka etsahala hore mokhoa o reriloeng o ka sebelisoa ho tseba eseng feela li-keystroke, empa le mefuta e meng ea data ea lekunutu e kentsoeng cache ea CPU. Tlhaselo e ka etsahala le haeba RDMA e holofetse, empa ntle le RDMA ts'ebetso ea eona e fokotsehile mme ts'ebetso e ba thata le ho feta. Hape hoa khoneha ho sebelisa DDIO ho hlophisa mocha oa puisano o patehileng o sebelisetsoang ho fetisetsa data ka mor'a hore seva se senyehe, se fetele mekhoa ea tšireletso.

Source: opennet.ru

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