{"id":55763,"date":"2020-01-28T00:00:00","date_gmt":"2020-01-27T21:00:00","guid":{"rendered":"https:\/\/prohoster.info\/blog\/blog_prohoster\/l1des-cacheout-i-vrs-novye-uyazvimosti-v-mikroarhitekturnyh-strukturah-cpu-intel"},"modified":"2020-02-18T14:03:54","modified_gmt":"2020-02-18T11:03:54","slug":"l1des-cacheout-i-vrs-novye-uyazvimosti-v-mikroarhitekturnyh-strukturah-cpu-intel","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/news\/l1des-cacheout-i-vrs-novye-uyazvimosti-v-mikroarhitekturnyh-strukturah-cpu-intel","title":{"rendered":"L1DES (CacheOut) dhe VRS \u2014 dob\u00ebsi t\u00eb reja n\u00eb strukturat mikroarkitektonike t\u00eb CPU-ve Intel","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Kompania Intel revealed<\/a><\/noindex> informacione mbi dy dob\u00ebsit\u00eb e reja n\u00eb CPU Intel, t\u00eb shkaktuara nga rrjedhja e t\u00eb dh\u00ebnave nga Cache L1D (CVE-2020-0549<\/a><\/noindex>, L1DES \u2014 L1D Eviction Sampling) dhe regjistrave vektorial\u00eb (CVE-2020-0548<\/a><\/noindex>, VRS \u2014 Vector Register Sampling). Vulnerabilitetet i p\u00ebrkasin klas\u00ebs MDS<\/a><\/noindex> (Microarchitectural Data Sampling) dhe bazohen n\u00eb p\u00ebrdorimin e metodave t\u00eb analiz\u00ebs p\u00ebrmes kanaleve t\u00eb jashtme p\u00ebr t\u00eb dh\u00ebnat n\u00eb strukturat mikroarkitekturore. AMD, ARM dhe procesor\u00ebt e tjer\u00eb nuk preken nga k\u00ebto probleme.<\/p>\n

Dob\u00ebsia m\u00eb e madhe paraqet dob\u00ebsia L1DES, e cila lejon<\/a><\/noindex> blloqet e t\u00eb dh\u00ebnave t\u00eb mbajtura n\u00eb cache (cache line), t\u00eb cilat b\u00ebhen t\u00eb z\u00ebvend\u00ebsuara nga cache i nivelit t\u00eb par\u00eb (L1D), n\u00eb bufferin e mbushjes (Fill Buffer), i cili n\u00eb k\u00ebt\u00eb pik\u00eb duhet t\u00eb jet\u00eb i zbraz\u00ebt. P\u00ebrdoren metoda t\u00eb analiz\u00ebs p\u00ebrmes kanaleve t\u00eb jashtme p\u00ebr t\u00eb p\u00ebrcaktuar t\u00eb dh\u00ebnat e mbajtura n\u00eb bufferin e mbushjes, t\u00eb propozuara m\u00eb par\u00eb n\u00eb sulmet MDS<\/a><\/noindex> (Microarchitectural Data Sampling) dhe TAA<\/a><\/noindex> (Transactional Asynchronous Abort). Natyra e mbrojtjes s\u00eb m\u00ebparshme nga
\nMDS dhe TAA ka qen\u00eb pastrimi i bufereve mikroarkitekturore para ndryshimit t\u00eb kontekstit, por, si\u00e7 ka dal\u00eb, n\u00ebn disa kushte t\u00eb dh\u00ebnat shfaqen spekulativisht n\u00eb bufer\u00ebt pas operacionit t\u00eb pastrimit, prandaj metodat MDS dhe TAA mbeten t\u00eb aplikueshme.<\/p>\n

\"L1DES<\/center><\/p>\n

Si rezultat, nj\u00eb sulmues mund t\u00eb arrij\u00eb t\u00eb p\u00ebrcaktoj\u00eb t\u00eb dh\u00ebnat e z\u00ebvend\u00ebsuara nga cache i nivelit t\u00eb par\u00eb, t\u00eb cilat jan\u00eb modifikuar gjat\u00eb ekzekutimit t\u00eb aplikacionit, i cili kishte mbajtur aktualisht b\u00ebrtham\u00ebn e CPU, ose aplikacione q\u00eb ekzekutohen paralelisht n\u00eb rrjetet logjik\u00eb t\u00eb tjera (hyperthread) n\u00eb t\u00eb nj\u00ebjt\u00ebn b\u00ebrtham\u00eb CPU (\u00e7aktivizimi i HyperThreading e zvog\u00eblon efikasitetin e sulmit). Ndryshe nga sulmi L1TF<\/a><\/noindex>, L1DES nuk lejon zgjedhjen e adresave fizike specifike p\u00ebr verifikim, por ofron mund\u00ebsin\u00eb p\u00ebr t\u00eb ndjekur n\u00eb m\u00ebnyr\u00eb pasive aktivitetin n\u00eb rrjetet logjik\u00eb t\u00eb tjera, n\u00eb lidhje me ngarkimin ose ruajtjen n\u00eb memorie t\u00eb vlerave.<\/p>\n

N\u00eb baz\u00eb t\u00eb L1DES, ekipe t\u00eb ndryshme k\u00ebrkuesish kan\u00eb zhvilluar disa variante sulmesh, t\u00eb cilat potencialisht lejojn\u00eb nxjerrjen e informacionit konfidencial nga procese t\u00eb tjera, sistemi operativ, makina virtuale dhe enclave t\u00eb mbrojtura SGX. <\/p>\n