Tawagar masu bincike daga Jami'ar Fasaha ta Graz (Austria), wacce aka sani a baya don haɓaka hare-haren MDS, NetSpectre, Throwhammer, da ZombieLoad, sun bayyana sabon hanyar kai hari ta hanyar tashoshi (CVE-2021-46778) wanda ke niyya ga layin masu tsara na'ura na AMD, waɗanda ake amfani da su don tsara umarni a cikin sassan aiwatar da CPU daban-daban. Harin, wanda aka yiwa lakabi da SQUIP, yana bawa mutum damar tantance bayanan da aka yi amfani da su wajen kididdigewa a cikin wani tsari ko na'ura mai kama-da-wane ko kafa hanyar sadarwa a boye tsakanin matakai ko na'urori masu kama-da-wane, yana ba da damar musayar bayanai ta ketare hanyoyin sarrafa hanyar shiga tsarin.
Batun yana shafar AMD CPUs dangane da na farko, na biyu, da na uku na Zen microarchitectures (AMD Ryzen 2000-5000, AMD Ryzen Threadripper, AMD Athlon 3000, AMD EPYC) lokacin amfani da multithreading lokaci guda (SMT). Na'urorin sarrafa Intel ba su da rauni ga harin saboda suna amfani da jerin gwano guda ɗaya, yayin da masu sarrafa AMD masu rauni ke amfani da layukan daban-daban ga kowane rukunin aiwatarwa. A matsayin hanyar da za a bi don toshe kwararar bayanan, AMD ta ba da shawarar cewa masu haɓakawa su yi amfani da algorithms waɗanda koyaushe suke aiwatar da lissafin lissafi a cikin lokaci akai-akai, ba tare da la’akari da yanayin bayanan da ake sarrafa su ba, kuma su guji yin reshe bisa mahimman bayanai.
Harin ya dogara ne akan tantance matakin jayayya a cikin jerin gwano daban-daban kuma ana gudanar da shi ta hanyar auna latency na fara ayyukan duba da aka aiwatar a cikin wani zaren SMT akan CPU na zahiri. An yi amfani da hanyar Prime+Probe don nazarin abubuwan da ke ciki, wanda ya haɗa da cika layi tare da saitin ƙididdiga da gano canje-canje ta hanyar auna lokutan shiga lokacin da aka sake cika layin.
A lokacin gwajin, masu binciken sun sami damar sake ƙirƙirar maɓallin RSA na sirri mai girman bit 4096 wanda aka yi amfani da shi don ƙirƙirar sa hannun dijital ta amfani da ɗakin karatu na ɓoye bayanai na mbedTLS 3.0, wanda ke amfani da algorithm na Montgomery don bayyana ma'auni. Tantance maɓallin yana buƙatar alamun 50500. Jimlar lokacin harin shine mintuna 38. An nuna bambance-bambancen hari waɗanda zasu iya zubar da bayanai tsakanin matakai daban-daban da injunan kama-da-wane waɗanda mai lura da yanayin ya sarrafa. KVMAn kuma nuna cewa ana iya amfani da hanyar don tsara ɓoyayyun canja wurin bayanai tsakanin injunan kama-da-wane a gudun 0.89 Mbit/s da kuma tsakanin hanyoyin aiki a gudun 2.70 Mbit/s tare da ƙimar kuskure ƙasa da 0.8%.
source: budenet.ru
