U-Daniel Antonioli, umcwaningi wezokuphepha we-Bluetooth owake wasungula izindlela zokuhlasela ze-BIAS, BLUR kanye ne-KNOB, uhlonze ubungozi obusha obubili (i-CVE-2023-24023) ohlelweni lwezingxoxo zeseshini ye-Bluetooth, okuthinta konke ukusetshenziswa kwe-Bluetooth okusekela izindlela Zokuxhumaniseka Okuvikelekile. " "Vikela Ukumatanisa Okulula", okuhambisana nokucaciswa kwe-Bluetooth Core 4.2-5.4. Njengokuboniswa kokusetshenziswa okungokoqobo kobungozi obuhlonziwe, izinketho eziyisi-6 zokuhlasela zenziwe ezisivumela ukuthi sihlangane phakathi kwamadivaysi e-Bluetooth abhanqwe ngaphambilini. Ikhodi esebenzisa izindlela zokuhlasela nezinsiza zokubheka ubungozi ishicilelwe ku-GitHub.
Ubungozi buphawulwe ngesikhathi sokuhlaziywa kwezinqubo ezichazwe ezingeni lokufinyelela imfihlo eya phambili (Imfihlo Yaphambili Nezayo), ephikisana nokufakwa ebucayini kokhiye beseshini esimweni sokunquma ukhiye ongunaphakade (ukubeka engcupheni omunye wokhiye abangunaphakade akufanele kuholele. ekususeni ukubethela kwamaseshini abanjwe ngaphambilini noma azayo) kanye nokusetshenziswa kabusha kokhiye beseshini (ukhiye osuka kwesinye isikhathi akufanele usebenze kwenye iseshini). Ubungozi obutholiwe bukwenza kube nokwenzeka ukweqa isivikelo esicacisiwe futhi kusetshenziswe kabusha ukhiye wesikhathi ongathembekile kumaseshini ahlukene. Ubungozi bubangelwa amaphutha esilinganisweni esiyisisekelo, akucaci ezitaki ze-Bluetooth ngazinye, futhi avela kuma-chip avela kubakhiqizi abahlukene.
Izindlela zokuhlasela ezihlongozwayo zisebenzisa izinketho ezihlukene zokuhlela ukukhwabanisa kwe-classic (i-LSC, i-Legacy Secure Connections esekelwe ezintweni zakudala ze-cryptographic primitives) futhi ezivikelekile (SC, Secure Connections okusekelwe ku-ECDH kanye ne-AES-CCM) uxhumano lwe-Bluetooth phakathi kwesistimu nedivayisi yocingo, njengoba kanye nokuhlela ukuxhumana kwe-MITM.ukuhlaselwa koxhumo kumamodi e-LSC kanye ne-SC. Kucatshangwa ukuthi konke ukusetshenziswa kwe-Bluetooth okuthobela izinga kungase kube lula kokuhlukile kokuhlasela kwe-BLUFFS. Indlela yaboniswa kumadivayisi angu-18 avela ezinkampanini ezifana ne-Intel, Broadcom, Apple, Google, Microsoft, CSR, Logitech, Infineon, Bose, Dell kanye ne-Xiaomi.
Ingqikithi yobungozi ikhuphukela emandleni, ngaphandle kokwephula izinga, ukuphoqa uxhumano ukuze lusebenzise imodi ye-LSC endala kanye nokhiye wesikhathi esifushane ongathembeki (SK), ngokucacisa ubuncane obungaba khona i-entropy phakathi nenqubo yezingxoxo zokuxhuma nokushaya indiva okuqukethwe kwempendulo enamapharamitha wokuqinisekisa (CR), okuholela ekukhiqizweni kokhiye weseshini ngokusekelwe kumapharamitha wokufaka unomphela (ukhiye weseshini u-SK ubalwa njenge-KDF kusukela kukhiye ongunaphakade (i-PK) namapharamitha okuvunyelwene ngawo phakathi neseshini) . Isibonelo, ngesikhathi sokuhlasela kwe-MITM, umhlaseli angashintsha amapharamitha 𝐴𝐶 kanye 𝑆𝐷 ngamavelu aziro phakathi nenqubo yengxoxo yeseshini, futhi asethe i-entropy 𝑆𝐸 ibe ngu-1, okuzoholela ekwakhekeni kokhiye weseshini 𝑆𝐾 ngokhiye wangempela. i-entropy ye-byte engu-1 (usayizi omncane ojwayelekile we-entropy ngamabhayithi angu-7 (amabhithi angu-56), obuqhathaniseka nokuthembeka ekukhethweni kokhiye we-DES).
Uma umhlaseli ekwazile ukuzuza ukusetshenziswa kokhiye omfushane phakathi kwezingxoxo zokuxhuma, lapho-ke angasebenzisa amandla aqinile ukuze anqume ukhiye ongunaphakade (i-PK) osetshenziselwa ukubethela futhi azuze ukuchithwa kwethrafikhi phakathi kwamadivayisi. Njengoba ukuhlasela kwe-MITM kungase kuqalise ukusetshenziswa kokhiye wokubethela ofanayo, uma lo khiye utholakala, ungasetshenziswa ukususa ukubethela zonke izikhathi ezidlule nezizayo ezivinjwe umhlaseli.
Ukuze kuvinjwe ubungozi, umcwaningi uhlongoze ukwenza izinguquko kuzinga elinweba iphrothokholi ye-LMP futhi kushintshwe ingqondo yokusebenzisa i-KDF (Umsebenzi Wokukhipha Ukhiye) lapho ukhiqiza okhiye kumodi ye-LSC. Ushintsho aluphuli ukuhambisana okubuyela emuva, kodwa lubangela ukuba umyalo we-LMP owandisiwe uvulwe futhi kuthunyelwe amabhayithi engeziwe angu-48. I-Bluetooth SIG, enesibopho sokuthuthukisa amazinga e-Bluetooth, iphakamise ukwenqaba ukuxhumana ngesiteshi sokuxhumana esibethelwe ngokhiye abafika kusayizi wamabhayithi angu-7 njengesinyathelo sokuphepha. Ukusetshenziswa okuhlala kusebenzisa Imodi Yokuvikela 4 Ileveli 4 kukhuthazwa ukuthi kwenqabe ukuxhumeka ngokhiye abafika kusayizi wamabhayithi angu-16.
Source: opennet.ru