{"id":101245,"date":"2021-09-10T22:22:37","date_gmt":"2021-09-10T20:22:37","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/uyazvimost-v-ghostscript-ekspluatiruemaya-cherez-imagemagick"},"modified":"2021-09-10T22:22:37","modified_gmt":"2021-09-10T20:22:37","slug":"uyazvimost-v-ghostscript-ekspluatiruemaya-cherez-imagemagick","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sk\/blog\/news\/uyazvimost-v-ghostscript-ekspluatiruemaya-cherez-imagemagick","title":{"rendered":"Zranite\u013enos\u0165 v Ghostscript, vykoris\u0165ovan\u00e1 prostredn\u00edctvom ImageMagick","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

V Ghostscripte, s\u00faprave n\u00e1strojov na spracovanie, konverziu a generovanie dokumentov vo form\u00e1toch PostScript a PDF, bola zisten\u00e1 kritick\u00e1 zranite\u013enos\u0165 (CVE-2021-3781), ktor\u00e1 umo\u017e\u0148uje vykonanie \u013eubovo\u013en\u00e9ho k\u00f3du pri spracovan\u00ed \u0161peci\u00e1lne form\u00e1tovan\u00e9ho s\u00faboru. Na probl\u00e9m p\u00f4vodne pouk\u00e1zal Emil Lerner, ktor\u00fd o zranite\u013enosti hovoril 25. augusta na konferencii ZeroNights X, ktor\u00e1 sa konala v Petrohrade (v predn\u00e1\u0161ke sa spomenulo, ako Emil v r\u00e1mci programov bug bounty vyu\u017eil t\u00fato zranite\u013enos\u0165 na z\u00edskanie odmien za demon\u0161tr\u00e1ciu \u00fatokov na slu\u017eby AirBNB, Dropbox a Yandex.Nehnute\u013enosti). <\/p>\n

5. septembra sa na internete objavil funk\u010dn\u00fd exploit, ktor\u00fd umo\u017e\u0148uje \u00fato\u010di\u0165 na syst\u00e9my s Ubuntu 20.04 prostredn\u00edctvom odovzdania \u0161peci\u00e1lne form\u00e1tovan\u00e9ho dokumentu, ktor\u00fd je nahrat\u00fd ako obr\u00e1zok, vykon\u00e1vaj\u00facemu webov\u00e9mu skriptu na serveri, ktor\u00fd pou\u017e\u00edva bal\u00edk php-imagemagick. Predbe\u017en\u00e9 \u00fadaje nazna\u010duj\u00fa, \u017ee tento exploit bol v ob\u011bhu u\u017e od marca. Bolo ozn\u00e1men\u00e9, \u017ee je mo\u017en\u00e9 \u00fato\u010di\u0165 na syst\u00e9my s GhostScript 9.50, no zistilo sa, \u017ee zranite\u013enos\u0165 sa prejavuje aj vo v\u0161etk\u00fdch nasleduj\u00facich verzi\u00e1ch GhostScript, vr\u00e1tane vo v\u00fdvoji nach\u00e1dzaj\u00facej sa verzie 9.55 z Gitu. <\/p>\n

Oprava bola navrhnut\u00e1 8. septembra a po recenzovan\u00ed bola prijat\u00e1 do repozit\u00e1ra GhostScript 9. septembra. V mnoh\u00fdch distrib\u00faci\u00e1ch probl\u00e9m st\u00e1le nie je opraven\u00fd (stav publikovania aktualiz\u00e1ci\u00ed si m\u00f4\u017eete pozrie\u0165 na str\u00e1nkach Debian, Ubuntu, Fedora, SUSE, RHEL, Arch Linux, FreeBSD, NetBSD). Uvo\u013enenie GhostScript s opravou zranite\u013enosti pl\u00e1nuj\u00fa zverejni\u0165 do konca mesiaca. <\/p>\n

Probl\u00e9m sp\u00f4sobila mo\u017enos\u0165 obch\u00e1dzania re\u017eimu izol\u00e1cie «-dSAFER» v d\u00f4sledku nedostato\u010dnej kontroly parametrov Postscript zariadenia «%pipe%», \u010do umo\u017enilo vykon\u00e1vanie \u013eubovo\u013en\u00fdch shellov\u00fdch pr\u00edkazov. Napr\u00edklad, na spustenie n\u00e1stroja id v dokumente sta\u010d\u00ed zada\u0165 riadok «(%pipe%\/tmp\/&id)(w)file» alebo «(%pipe%\/tmp\/;id)(r)file». <\/p>\n

Pripom\u00edname, \u017ee zranite\u013enosti v Ghostscript predstavuj\u00fa zv\u00fd\u0161en\u00e9 riziko, preto\u017ee tento bal\u00edk sa pou\u017e\u00edva v mnoh\u00fdch popul\u00e1rnych aplik\u00e1ci\u00e1ch na spracovanie form\u00e1tov PostScript a PDF. Napr\u00edklad, Ghostscript je vyvol\u00e1van\u00fd po\u010das vytv\u00e1rania n\u00e1h\u013eadov na pracovnej ploche, pri pozad\u00ed indexovan\u00ed d\u00e1t a pri prevode obr\u00e1zkov. Pre \u00faspe\u0161n\u00fd \u00fatok je v mnoh\u00fdch pr\u00edpadoch sta\u010d\u00ed jednoducho nahra\u0165 s\u00fabor s exploitom alebo si prezrie\u0165 adres\u00e1r s n\u00edm vo spr\u00e1vci s\u00faborov, ktor\u00fd podporuje zobrazenie n\u00e1h\u013eadov dokumentov, ako napr\u00edklad Nautilus. <\/p>\n

Zranite\u013enosti v Ghostscript je mo\u017en\u00e9 tie\u017e zneu\u017ei\u0165 prostredn\u00edctvom spracovate\u013eov obr\u00e1zkov zalo\u017een\u00fdch na bal\u00edkoch ImageMagick a GraphicsMagick, ak im odovzd\u00e1te JPEG alebo PNG s\u00fabor, v ktorom sa namiesto obr\u00e1zku nach\u00e1dza k\u00f3d PostScript (tak\u00fdto s\u00fabor bude spracovan\u00fd v Ghostscript, preto\u017ee MIME typ sa rozpozn\u00e1va pod\u013ea obsahu, nie na z\u00e1klade pr\u00edpony).
\n
Zdroj: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u0412 Ghostscript, \u043d\u0430\u0431\u043e\u0440\u0435 \u0438\u043d\u0441\u0442\u0440\u0443\u043c\u0435\u043d\u0442\u043e\u0432 \u0434\u043b\u044f \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u043a\u0438, \u043f\u0440\u0435\u043e\u0431\u0440\u0430\u0437\u043e\u0432\u0430\u043d\u0438\u044f \u0438 \u0433\u0435\u043d\u0435\u0440\u0430\u0446\u0438\u0438 \u0434\u043e\u043a\u0443\u043c\u0435\u043d\u0442\u043e\u0432 \u0432 \u0444\u043e\u0440\u043c\u0430\u0442\u0430\u0445 PostScript \u0438 PDF, \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u043a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0430\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2021-3781), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u0432\u044b\u043f\u043e\u043b\u043d\u0438\u0442\u044c \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u043b\u044c\u043d\u044b\u0439 \u043a\u043e\u0434 \u043f\u0440\u0438 \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u043a\u0435 \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u043e\u0444\u043e\u0440\u043c\u043b\u0435\u043d\u043d\u043e\u0433\u043e \u0444\u0430\u0439\u043b\u0430. \u0418\u0437\u043d\u0430\u0447\u0430\u043b\u044c\u043d\u043e \u043d\u0430 \u043d\u0430\u043b\u0438\u0447\u0438\u0435 \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u044b \u043e\u0431\u0440\u0430\u0442\u0438\u043b \u0432\u043d\u0438\u043c\u0430\u043d\u0438\u0435 \u042d\u043c\u0438\u043b\u044c \u041b\u0435\u0440\u043d\u0435\u0440, \u043a\u043e\u0442\u043e\u0440\u044b\u0439 \u0440\u0430\u0441\u0441\u043a\u0430\u0437\u0430\u043b \u043e\u0431 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 25 \u0430\u0432\u0433\u0443\u0441\u0442\u0430 \u043d\u0430 \u043f\u0440\u043e\u0448\u0435\u0434\u0448\u0435\u0439 \u0432 \u0421\u0430\u043d\u043a\u0442-\u041f\u0435\u0442\u0435\u0440\u0431\u0443\u0440\u0433\u0435 \u043a\u043e\u043d\u0444\u0435\u0440\u0435\u043d\u0446\u0438\u0438 ZeroNights X (\u0432 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PDF, bola zisten\u00e1 kritick\u00e1 zranite\u013enos\u0165 (CVE-2021-3781), ktor\u00e1 umo\u017e\u0148uje vykonanie svojvo\u013en\u00e9ho k\u00f3du pri.","canonical_url":"https:\/\/prohoster.info\/sk\/blog\/news\/uyazvimost-v-ghostscript-ekspluatiruemaya-cherez-imagemagick","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"sk_SK","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432 Ghostscript, \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0438\u0440\u0443\u0435\u043c\u0430\u044f \u0447\u0435\u0440\u0435\u0437 ImageMagick | 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