N\u00eb PuTTY, klienti p\u00ebr protokollin SSH i p\u00ebrdorur gjer\u00ebsisht n\u00eb platform\u00ebn Windows, \u00ebsht\u00eb zbuluar nj\u00eb cenueshm\u00ebri e rrezikshme (CVE-2024-31497) q\u00eb lejon rikrijimin e \u00e7el\u00ebsit privat t\u00eb p\u00ebrdoruesit, t\u00eb gjeneruar me algoritmin ECDSA dhe kurb\u00ebn eliptike NIST P-521 (ecdsa-sha2-nistp521). P\u00ebr t\u00eb nxjerr\u00eb \u00e7el\u00ebsin privat, mjafton t\u00eb analizohen rreth 60 n\u00ebnshkrime dixhitale t\u00eb krijuara me \u00e7el\u00ebsin e prekur. <\/p>\n
Vulnerabiliteti shfaqet q\u00eb nga versi PuTTY 0.68 dhe gjithashtu ka prekur produkte, t\u00eb cilat p\u00ebrfshijn\u00eb versione t\u00eb cenueshme t\u00eb PuTTY, si\u00e7 jan\u00eb FileZilla (3.24.1 — 3.66.5), WinSCP (5.9.5 — 6.3.2), TortoiseGit (2.4.0.2 — 2.15.0) dhe TortoiseSVN (1.10.0 — 1.14.6). Problemi \u00ebsht\u00eb zgjidhur n\u00eb p\u00ebrdit\u00ebsimet e PuTTY 0.81, FileZilla 3.67.0, WinSCP 6.3.3 dhe TortoiseGit 2.15.0. Pas instalimit t\u00eb p\u00ebrdit\u00ebsimit, p\u00ebrdoruesve u rekomandohet t\u00eb gjenerojn\u00eb \u00e7el\u00ebsa t\u00eb rinj dhe t\u00eb fshijn\u00eb \u00e7el\u00ebsat e vjet\u00ebr publik nga skedaret authorized_keys. <\/p>\n
Cenueshm\u00ebria u shkaktua nga pakujdesia e zhvilluesve, t\u00eb cil\u00ebt p\u00ebr gjenerimin e nj\u00eb \u00e7el\u00ebsi 521-bit p\u00ebrdor\u00ebn nj\u00eb nonce t\u00eb bazuar n\u00eb nj\u00eb sekuenc\u00eb t\u00eb rast\u00ebsishme 512-bit, me shum\u00eb gjas\u00eb duke supozuar se entropia prej 512 bit\u00ebsh ishte e mjaftueshme dhe se 9 bit\u00ebt e mbetur nuk kishin r\u00ebnd\u00ebsi thelb\u00ebsore. Si rezultat, n\u00eb t\u00eb gjith\u00eb \u00e7el\u00ebsat privat\u00eb t\u00eb krijuar n\u00eb PuTTY me algoritmin ecdsa-sha2-nistp521, 9 bit\u00ebt e par\u00eb t\u00eb nonce gjithmon\u00eb merrnin vlera zero. <\/p>\n
P\u00ebr ECDSA dhe DSA, cil\u00ebsia e gjeneratorit t\u00eb numrave pseudorast\u00ebsor\u00eb dhe mbulimi i plot\u00eb me t\u00eb dh\u00ebna t\u00eb rast\u00ebsishme i parametrit t\u00eb p\u00ebrdorur n\u00eb llogaritjen e modulit kan\u00eb r\u00ebnd\u00ebsi vendimtare, sepse p\u00ebrcaktimi qoft\u00eb edhe i disa biteve me informacion mbi nonce mjafton p\u00ebr t\u00eb kryer nj\u00eb sulm me rikuperim t\u00eb nj\u00ebpasnj\u00ebsh\u00ebm t\u00eb t\u00eb gjith\u00eb \u00e7el\u00ebsit privat. P\u00ebr rikuperimin me sukses t\u00eb \u00e7el\u00ebsit mjafton t\u00eb disponohet \u00e7el\u00ebsi publik dhe t\u00eb analizohen disa dhjet\u00ebra n\u00ebnshkrime dixhitale t\u00eb gjeneruara me \u00e7el\u00ebsin e prekur p\u00ebr t\u00eb dh\u00ebna t\u00eb njohura nga sulmuesi. Sulmi reduktohet n\u00eb zgjidhjen e problemit HNP (Hidden Number Problem). <\/p>\n
N\u00ebnshkrimet dixhitale t\u00eb nevojshme mund t\u00eb merren, p\u00ebr shembull, kur p\u00ebrdoruesi lidhet me serverin SSH t\u00eb sulmuesit ose me nj\u00eb server Git q\u00eb p\u00ebrdor SSH si transport. N\u00ebnshkrimet e nevojshme p\u00ebr sulmin mund t\u00eb zbulohen edhe n\u00ebse \u00e7el\u00ebsi \u00ebsht\u00eb p\u00ebrdorur p\u00ebr t\u00eb n\u00ebnshkruar t\u00eb dh\u00ebna arbitrare, p\u00ebr shembull git commit-e, gjat\u00eb p\u00ebrdorimit t\u00eb agjentit SSH Pageant p\u00ebr t\u00eb ridrejtuar trafikun te hosti i zhvilluesit. Marrja e t\u00eb dh\u00ebnave t\u00eb nevojshme p\u00ebr rikuperimin e \u00e7el\u00ebsit gjat\u00eb nj\u00eb sulmi MITM p\u00ebrjashtohet, pasi n\u00ebnshkrimet n\u00eb SSH nuk transmetohen n\u00eb form\u00eb t\u00eb hapur. <\/p>\n
Vihet n\u00eb dukje se nj\u00eb p\u00ebrdorim i ngjash\u00ebm i vektor\u00ebve jo t\u00eb plot\u00eb t\u00eb inicializimit \u00ebsht\u00eb p\u00ebrdorur n\u00eb PuTTY edhe p\u00ebr lloje t\u00eb tjera t\u00eb kurbave eliptike, por p\u00ebr algoritme t\u00eb ndryshme nga ECDSA P-521, rrjedhjet e informacionit q\u00eb kan\u00eb ndodhur nuk mjaftojn\u00eb p\u00ebr t\u00eb realizuar nj\u00eb sulm funksional p\u00ebr rikuperimin e \u00e7el\u00ebsit. \u00c7el\u00ebsat ECDSA me madh\u00ebsi t\u00eb tjera dhe \u00e7el\u00ebsat Ed25519 nuk preken nga ky sulm. \n Burimi: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"