{"id":99693,"date":"2021-04-09T16:22:51","date_gmt":"2021-04-09T14:22:51","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/uyazvimosti-v-podsisteme-ebpf-yadra-linux"},"modified":"2021-04-09T16:22:51","modified_gmt":"2021-04-09T14:22:51","slug":"uyazvimosti-v-podsisteme-ebpf-yadra-linux","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/novosti-interneta\/uyazvimosti-v-podsisteme-ebpf-yadra-linux","title":{"rendered":"Vulnerabilitetet n\u00eb n\u00ebn-sistemin e eBPF t\u00eb b\u00ebrtham\u00ebs Linux.","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
N\u00eb n\u00ebn-sistemin e eBPF, i cili lejon ekzekutimin e trajtuesve p\u00ebr gjurmimin, analizimin e funksionimit t\u00eb n\u00ebn-sistemeve dhe menaxhimin e trafikut, q\u00eb realizohen brenda kernelit t\u00eb Linux n\u00eb nj\u00eb makin\u00eb virtuale speciale me JIT, \u00ebsht\u00eb zbuluar nj\u00eb vulnerabilitet (CVE-2021-29154), i cili lejon nj\u00eb p\u00ebrdorues lokal t\u00eb arrij\u00eb ekzekutimin e kodit t\u00eb tij n\u00eb nivelin e kernelit. Problemi shfaqet deri n\u00eb versionin 5.11.12 (p\u00ebrfshir\u00eb) dhe ende nuk \u00ebsht\u00eb rregulluar n\u00eb distro (Debian, Ubuntu, RHEL, Fedora, SUSE, Arch). Nj\u00eb rregullim \u00ebsht\u00eb n\u00eb dispozicion si nj\u00eb patch. <\/p>\n
Sipas deklaratave t\u00eb hulumtuesve q\u00eb zbuluan vulnerabilitetin, ata arrit\u00ebn t\u00eb zhvillojn\u00eb nj\u00eb prototip funksional t\u00eb eksploitit p\u00ebr sistemet 32- dhe 64-bit x86, i cili mund t\u00eb p\u00ebrdoret nga nj\u00eb p\u00ebrdorues me privilegje t\u00eb kufizuara. N\u00eb k\u00ebt\u00eb kontekst, kompania Red Hat v\u00eb n\u00eb dukje se rreziku i problemit varet nga disponueshm\u00ebria e sistemit t\u00eb thirrjes eBPF p\u00ebr p\u00ebrdoruesin. P\u00ebr shembull, n\u00eb RHEL dhe shumic\u00ebn e distro t\u00eb tjera t\u00eb Linux n\u00eb konfigurimin e tyre baz\u00eb, vulnerabiliteti mund t\u00eb shfryt\u00ebzohet n\u00ebse BPF JIT \u00ebsht\u00eb aktiv dhe p\u00ebrdoruesi ka t\u00eb drejtat CAP_SYS_ADMIN. Si mas\u00eb mbrojt\u00ebse, rekomandohet t\u00eb \u00e7aktivizohet BPF JIT duke p\u00ebrdorur komand\u00ebn: echo 0 > \/proc\/sys\/net\/core\/bpf_jit_enable <\/p>\n
Problemi shkaktohet nga nj\u00eb gabim n\u00eb llogaritjen e zhvendosjes p\u00ebr komandat e deges\u00ebs n\u00eb procesin e gjenerimit t\u00eb kodit makinerik nga kompajleri JIT. K\u00ebshtu, gjat\u00eb gjenerimit t\u00eb instruktivave t\u00eb deges\u00ebs nuk merret parasysh se zhvendosja mund t\u00eb ndryshoj\u00eb pas kalimit n\u00eb faz\u00ebn e optimizimit. Kjo mang\u00ebsi mund t\u00eb p\u00ebrdoret p\u00ebr t\u00eb formuar kod makinerik anormal dhe p\u00ebr ta ekzekutuar at\u00eb n\u00eb nivelin e kernelit. <\/p>\n
E r\u00ebnd\u00ebsishme \u00ebsht\u00eb se kjo nuk \u00ebsht\u00eb e vetmja vulnerabilitet n\u00eb n\u00ebn-sistemin e eBPF gjat\u00eb k\u00ebtij koh\u00eb. N\u00eb fund t\u00eb marsit, n\u00eb kernel u identifikuan edhe dy vulnerabilitete t\u00eb tjera (CVE-2020-27170, CVE-2020-27171), q\u00eb ofrojn\u00eb mund\u00ebsin\u00eb e p\u00ebrdorimit t\u00eb eBPF p\u00ebr t\u00eb anashkaluar mbrojtjen nga vulnerabilitetet e klas\u00ebs Spectre, t\u00eb cilat lejojn\u00eb p\u00ebrcaktimin e p\u00ebrmbajtjes s\u00eb memories s\u00eb kernelit si rezultat i krijimit t\u00eb kushteve p\u00ebr ekzekutimin spekulativ t\u00eb operacioneve t\u00eb caktuara. P\u00ebr nj\u00eb sulm Spectre k\u00ebrkohet q\u00eb n\u00eb kodin me privilegje t\u00eb ket\u00eb nj\u00eb sekuenc\u00eb t\u00eb caktuar komandash q\u00eb \u00e7on n\u00eb ekzekutimin spekulativ t\u00eb instruksioneve. N\u00eb eBPF jan\u00eb gjetur disa m\u00ebnyra p\u00ebr t\u00eb gjeneruar k\u00ebto instruksione p\u00ebrmes manipulimeve me programet BPF q\u00eb d\u00ebrgohen p\u00ebr ekzekutim. <\/p>\n
Vulnerabiliteti CVE-2020-27170 shkaktohet nga manipulimet me treguesit n\u00eb verifikuesin BPF, q\u00eb shkaktojn\u00eb operacione spekulative p\u00ebr qasjen n\u00eb zona jasht\u00eb kufijve t\u00eb buffer-it. Vulnerabiliteti CVE-2020-27171 lidhet me nj\u00eb gabim n\u00eb aritmetiken e numrave t\u00eb plot\u00eb (integer underflow) gjat\u00eb pun\u00ebs me treguesit, q\u00eb shkakton qasje spekulative n\u00eb t\u00eb dh\u00ebna jasht\u00eb buffer-it. K\u00ebto probleme tashm\u00eb jan\u00eb rregulluar n\u00eb versionet e kernelit 5.11.8, 5.10.25, 5.4.107, 4.19.182 dhe 4.14.227, dhe jan\u00eb p\u00ebrfshir\u00eb n\u00eb p\u00ebrdit\u00ebsimet e kernelit t\u00eb shumic\u00ebs s\u00eb distro t\u00eb Linux. Hulumtuesit kan\u00eb p\u00ebrgatitur nj\u00eb prototip eksploiti, i cili lejon nj\u00eb p\u00ebrdorues t\u00eb pafavorsh\u00ebm t\u00eb nxjerr\u00eb t\u00eb dh\u00ebna nga memoria e kernelit. \n Burimi: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"