{"id":103411,"date":"2022-02-22T15:37:00","date_gmt":"2022-02-22T13:37:00","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/uyazvimost-v-podsisteme-netfilter-pozvolyayushhaya-vypolnit-kod-na-urovne-yadra-linux"},"modified":"2022-02-22T15:37:00","modified_gmt":"2022-02-22T13:37:00","slug":"uyazvimost-v-podsisteme-netfilter-pozvolyayushhaya-vypolnit-kod-na-urovne-yadra-linux","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/novosti-interneta\/uyazvimost-v-podsisteme-netfilter-pozvolyayushhaya-vypolnit-kod-na-urovne-yadra-linux","title":{"rendered":"Vulnerabilitet n\u00eb n\u00ebnsistemin netfilter, q\u00eb lejon ekzekutimin e kodit n\u00eb nivelin e kernelit Linux","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
N\u00eb Netfilter, n\u00ebnsistemi i kernelit Linux i p\u00ebrdorur p\u00ebr filtrimin dhe modifikimin e paketave rrjet, \u00ebsht\u00eb zbuluar nj\u00eb vulnerabilitet (CVE-2022-25636) q\u00eb lejon ekzekutimin e kodit n\u00eb nivelin e kernelit. \u00cbsht\u00eb njoftuar p\u00ebr nj\u00eb shembull eksploati q\u00eb lejon nj\u00eb p\u00ebrdorues lokal t\u00eb rris\u00eb privilegjet e tij n\u00eb Ubuntu 21.10 me mekanizmin KASLR t\u00eb fikur. Problemi paraqitet q\u00eb nga kernel 5.4. Nj\u00eb korrigjim aktualisht \u00ebsht\u00eb n\u00eb dispozicion si nj\u00eb patch (l\u00ebshimet e korigjuara t\u00eb kernelit nuk jan\u00eb formuar). Muni t\u00eb ndiqni publikimin e p\u00ebrdit\u00ebsimeve n\u00eb paketat n\u00eb shp\u00ebrndarjet e m\u00ebposhtme: Debian, SUSE, Ubuntu, RHEL, Fedora, Gentoo, Arch Linux. <\/p>\n
Vulnerabiliteti shkaktohet nga nj\u00eb gabim n\u00eb llogaritjen e madh\u00ebsis\u00eb s\u00eb arrave flow->rule->action.entries n\u00eb funksionin nft_fwd_dup_netdev_offload (i p\u00ebrcaktuar n\u00eb skedarin net\/netfilter\/nf_dup_netdev.c), i cili mund t\u00eb rezultoj\u00eb n\u00eb shkruarjen e t\u00eb dh\u00ebnave t\u00eb kontrolluara nga sulmuesi n\u00eb nj\u00eb zon\u00eb memorjeje p\u00ebrtej tamponit t\u00eb ndar\u00eb. Gabimi shfaqet gjat\u00eb konfigurimit t\u00eb rregullave 'dup' dhe 'fwd' n\u00eb lidhje, p\u00ebr t\u00eb cilat aplikohet p\u00ebrshpejtimi harduerik i p\u00ebrpunimit t\u00eb paketave (offload). Pasi mbingarkesa ndodh n\u00eb faz\u00ebn p\u00ebrpara krijimit t\u00eb rregullit t\u00eb filtrimit t\u00eb paketave dhe verifikimit t\u00eb mb\u00ebshtetjes p\u00ebr offload, vulnerabiliteti \u00ebsht\u00eb gjithashtu i aplikuesh\u00ebm p\u00ebr pajisjet rrjet\u00ebsore q\u00eb nuk mb\u00ebshtesin p\u00ebrshpejtimin harduerik, si interface loopback. <\/p>\n
V\u00ebrehet se problemi \u00ebsht\u00eb mjaft i thjesht\u00eb p\u00ebr t'u eksplautuar, pasi q\u00eb vlerat q\u00eb dalin jasht\u00eb tamponit mund t\u00eb rishkruajn\u00eb treguesin n\u00eb struktur\u00ebn net_device, dhe t\u00eb dh\u00ebnat p\u00ebr vler\u00ebn e rishkruar kthehen n\u00eb hap\u00ebsir\u00ebn e p\u00ebrdoruesit, duke lejuar m\u00ebsimin e adresave t\u00eb nevojshme p\u00ebr t\u00eb kryer sulmin. P\u00ebr t\u00eb shfryt\u00ebzuar vulnerabilitetin nevojitet krijimi i rregullave t\u00eb caktuara n\u00eb nftables, gj\u00eb q\u00eb \u00ebsht\u00eb e mundur vet\u00ebm me privilegjet CAP_NET_ADMIN, t\u00eb cilat mund t\u00eb fitojn\u00eb nj\u00eb p\u00ebrdorues i pa privilegjuar n\u00eb nj\u00eb hap\u00ebsir\u00eb rrjeti t\u00eb ve\u00e7ant\u00eb (network namespaces). Vulnerabiliteti gjithashtu mund t\u00eb p\u00ebrdoret p\u00ebr sulme ndaj sistemeve t\u00eb izolimit t\u00eb konteiner\u00ebve. \n Burimi: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"