{"id":53507,"date":"2017-11-28T18:04:11","date_gmt":"2017-11-28T10:04:11","guid":{"rendered":"https:\/\/blog.trendmicro.com.tw\/?p=53507"},"modified":"2017-11-28T18:04:11","modified_gmt":"2017-11-28T10:04:11","slug":"systemd%e6%bc%8f%e6%b4%9e%e5%9c%a8linux%e4%b8%8a%e5%b0%8e%e8%87%b4%e9%98%bb%e6%96%b7%e6%9c%8d%e5%8b%99%e6%94%bb%e6%93%8a","status":"publish","type":"post","link":"https:\/\/blog.trendmicro.com.tw\/?p=53507","title":{"rendered":"systemd\u6f0f\u6d1e\u5728Linux\u4e0a\u5c0e\u81f4\u963b\u65b7\u670d\u52d9\u653b\u64ca"},"content":{"rendered":"<p><img decoding=\"async\" class=\"alignleft\" src=\"https:\/\/blog.trendmicro.com\/trendlabs-security-intelligence\/files\/2016\/09\/feature_vul-200x200.jpg\" \/>\u8a31\u591aLinux\u767c\u884c\u7248\u90fd\u56e0\u70ba\u6700\u8fd1\u88ab\u62ab\u9732\u7684<a href=\"https:\/\/github.com\/systemd\/systemd\/\"><em>systemd<\/em><\/a>\u7684\u6f0f\u6d1e\u800c\u9762\u81e8\u5371\u96aa\uff1aDNS\u89e3\u6790\u670d\u52d9\u7684\u4e00\u500b\u6f0f\u6d1e\u53ef\u80fd\u8b93\u7cfb\u7d71\u906d\u53d7<a href=\"https:\/\/blog.trendmicro.com.tw\/?p=16497\">\u5206\u6563\u5f0f\u963b\u65b7\u670d\u52d9\u653b\u64ca (DDoS)<\/a>\u3002\u653b\u64ca\u9019\u6f0f\u6d1e\u7684\u65b9\u5f0f\u662f\u8b93\u7cfb\u7d71\u5411\u653b\u64ca\u8005\u6240\u63a7\u5236\u7684DNS\u4f3a\u670d\u5668\u9032\u884c\u67e5\u8a62\u3002DNS\u4f3a\u670d\u5668\u63a5\u8457\u9001\u56de\u4e00\u500b\u7279\u88fd\u56de\u61c9\uff0c\u8b93systemd\u9032\u5165\u7121\u9650\u8ff4\u5708\uff0c\u4e5f\u8b93\u7cfb\u7d71\u7684CPU\u4f7f\u7528\u7387\u6301\u7e8c\u5728100%\u7684\u72c0\u614b\u3002\u9019\u6f0f\u6d1e\u5df2\u7d93\u88ab\u5206\u914d\u7de8\u865f<a href=\"https:\/\/cve.mitre.org\/cgi-bin\/cvename.cgi?name=CVE-2017-15908\">CVE-2017-15908<\/a>\u3002<\/p>\n<p>\u6709\u8a31\u591a\u65b9\u6cd5\u53ef\u4ee5\u8b93\u4f7f\u7528\u8005\u67e5\u8a62\u60e1\u610f\u4efd\u5b50\u6240\u63a7\u5236\u7684DNS\u4f3a\u670d\u5668\uff0c\u4e0d\u904e\u6700\u7c21\u55ae\u7684\u4f5c\u6cd5\u662f\u8b93\u4f7f\u7528\u8005\u7cfb\u7d71\u9023\u5f80\u653b\u64ca\u8005\u6240\u63a7\u5236\u7684\u7db2\u57df\u3002\u9019\u53ef\u4ee5\u900f\u904e\u60e1\u610f\u8edf\u9ad4\u6216\u793e\u4ea4\u5de5\u7a0b\u5b8c\u6210\u3002<\/p>\n<p>\u89e3\u6c7a\u9019\u6f0f\u6d1e\u6700\u6709\u6548\u7684\u8fa6\u6cd5\u662f\u4fee\u88dc<em>systemd<\/em>\u7684\u6f0f\u6d1e\u3002<a href=\"https:\/\/www.trendmicro.com.tw\/edm\/Tracking.asp?id=2651&amp;name=20110916\">\u8da8\u52e2\u79d1\u6280<\/a>\u5728\u4eca\u5e747\u6708\u9996\u5148\u767c\u73fe\u4e86\u9019\u500b\u6f0f\u6d1e\uff0c\u4e26\u5728\u540c\u6708\u4efd\u901a\u904e\u96f6\u6642\u5dee\u8a08\u756b\uff08ZDI\uff09\u56de\u5831\u7d66\u9069\u7576\u7684\u5ee0\u5546\u3002\u7368\u7acb\u7814\u7a76\u4eba\u54e1\u5728<a href=\"https:\/\/bugs.launchpad.net\/ubuntu\/%2Bsource\/systemd\/%2Bbug\/1725351\">\u4eca\u5e7410\u6708<\/a>\u4e5f\u540c\u6a23\u767c\u73fe\u4e86\u9019\u500b\u6f0f\u6d1e\uff0c\u4e26\u5c07\u5176\u56de\u5831\u7d66Canonical\u3002\u8a31\u591aLinux\u767c\u884c\u7248\u90fd\u5df2\u7d93\u63a8\u51fa\u4fee\u5fa9\u7a0b\u5f0f\uff0c\u50cfUbuntu\u4e5f\u5728<a href=\"https:\/\/usn.ubuntu.com\/usn\/usn-3466-1\/\">10\u6708\u5e95<\/a>\u767c\u5e03\u3002\u5e78\u904b\u7684\u662f\uff0c\u5230\u76ee\u524d\u70ba\u6b62\u9084\u6c92\u6709\u51fa\u73fe\u91dd\u5c0d\u6b64\u6f0f\u6d1e\u7684\u653b\u64ca\u3002<\/p>\n<p>&nbsp;<\/p>\n<p><strong><em>\u6f0f\u6d1e\u5206\u6790<\/em><\/strong><\/p>\n<p>\u96a8\u8457\u6642\u9593\u904e\u53bb\uff0cDNS\u6703\u6301\u7e8c\u52a0\u5165\u65b0\u7684\u529f\u80fd\uff0c\u65e2\u662f\u70ba\u4e86\u589e\u52a0\u65b0\u529f\u80fd\u4e5f\u662f\u70ba\u4e86\u8b93\u5176\u66f4\u52a0\u5b89\u5168\u3002\u4e00\u500b\u5b9a\u7fa9\u5728<a href=\"https:\/\/www.ietf.org\/rfc\/rfc4034.txt\">RFC 4034<\/a>\u5167\uff0c\u65b0\u52a0\u5165\u57df\u540d\u5b89\u5168\u64f4\u5c55\uff08DNSSEC\uff09\u7684\u8cc7\u6e90\u8a18\u9304\u985e\u578b\u7a31\u70baNSEC\uff08Next Secure\uff09\u8a18\u9304\u3002<\/p>\n<p>\u9019\u6f0f\u6d1e\u767c\u751f\u5728\u8655\u7406\u8868\u793aNSEC\u4f4d\u5143\u5716\uff08bitmap\uff09\u4e2d\u865b\u64ec\u578b\u614b\uff08pseudo-type\uff09\u7684\u4f4d\u5143\u6642\u3002\u4e0b\u5716\u986f\u793a\u4e86\u7a0b\u5f0f\u78bc\u5340\u584a\u548c\u5806\u758a\u6846\u67b6\u3002\u53cd\u767d\u7684\u5730\u65b9\u201ccontinue\u201d\u986f\u793a\u201cwhile\u8ff4\u5708\u201d\u9032\u5165\u7121\u9650\u8ff4\u5708\u3002<em>dns_packet_read_type_window()<\/em>\u51fa\u73fe\u5728<em>resolved-dns-packet.c<\/em>\u5167\u3002<!--more--><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/blog.trendmicro.com\/trendlabs-security-intelligence\/files\/2017\/11\/systemd-1tb.png\" \/><\/p>\n<p><em>\u57161<\/em><em>\u3001\u7121\u9650\u8ff4\u5708\u7684\u539f\u59cb\u78bc\u548c\u5806\u758a\u6846\u67b6<\/em><\/p>\n<p>&nbsp;<\/p>\n<p>\u8acb\u6ce8\u610f\uff0c\u4e0a\u8ff0\u51fd\u5f0f<em>dns_packet_read_type_window()<\/em>\u662f\u7576\u8a18\u9304\u985e\u578b\u70baDNS_TYPE_NSEC\u6642\u7531<em>dns_packet_read_rr()<\/em>\u547c\u53eb\u3002\u4e0b\u5716\u986f\u793a\u4e86<em>resolve-dns-packet.c<\/em>\u5167<em>dns_packet_read_rr()<\/em>\u7684\u7a0b\u5f0f\u78bc\u5340\u584a\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/blog.trendmicro.com\/trendlabs-security-intelligence\/files\/2017\/11\/systemd-2tb.png\" \/><\/p>\n<p><em>\u57162<\/em><em>\u3001\u8b80\u53d6DNS<\/em><em>\u5c01\u5305\u7684\u539f\u59cb\u78bc<\/em><\/p>\n<p>&nbsp;<\/p>\n<p><strong><em>\u6982\u5ff5\u8b49\u660e\uff08POC<\/em><\/strong><strong><em>\uff09<\/em><\/strong><\/p>\n<p>\u70ba\u4e86\u6e2c\u8a66\u9019\u500b\u6f0f\u6d1e\uff0c\u6211\u5011\u67b6\u8a2d\u4e00\u500b\u6703\u7528\u60e1\u610f\u683c\u5f0f\u56de\u61c9\u7684DNS\u4f3a\u670d\u5668\u3002\u9019\u56de\u61c9\u5305\u542b\u8a2d\u8a08\u4f86\u89f8\u767c\u9019\u6f0f\u6d1e\u7684NSEC\u8a18\u9304\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/blog.trendmicro.com\/trendlabs-security-intelligence\/files\/2017\/11\/systemd-3tb.png\" \/><\/p>\n<p><em>\u57163<\/em><em>\u3001\u7279\u88fdDNS<\/em><em>\u56de\u61c9\u7684\u5c01\u5305<\/em><\/p>\n<p>&nbsp;<\/p>\n<p>\u4e00\u65e6\u904b\u884c<em>systemd<\/em>\u7684\u7cfb\u7d71\u7528\u5b83\u4f86\u9032\u884cDNS\u89e3\u6790\uff0c\u5c31\u6703\u6536\u5230\u9019\u689d\u7279\u88fd\u7684DNS\u5c01\u5305\uff0c\u8b93CPU\u4f7f\u7528\u7387\u9054\u5230100%\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/blog.trendmicro.com\/trendlabs-security-intelligence\/files\/2017\/11\/systemd-4tb.png\" \/><\/p>\n<p><em>\u57164<\/em><em>\u3001CPU<\/em><em>\u4f7f\u7528\u7387\u8b8a\u5230\u6700\u5927<\/em><\/p>\n<p>&nbsp;<\/p>\n<p><strong><em>\u7de9\u89e3\u63aa\u65bd<\/em><\/strong><\/p>\n<p>\u6b63\u5982\u6211\u5011\u524d\u9762\u6240\u63d0\u5230\uff0c\u6b64\u6f0f\u6d1e\u7684\u4fee\u5fa9\u7a0b\u5f0f\u5df2\u7d93\u767c\u5e03\u3002\u5efa\u8b70\u6709\u98a8\u96aa\u7684\u7cfb\u7d71\u8981\u76e1\u5feb\u66f4\u65b0\u3002<\/p>\n<p>\u7cfb\u7d71\u7ba1\u7406\u54e1\u4e5f\u53ef\u4ee5\u9078\u64c7\u624b\u52d5\u5c01\u9396\u53ef\u80fd\u7684\u60e1\u610f\u5c01\u5305\u3002\u6aa2\u67e5\u50b3\u5165\u7684DNS\u56de\u61c9\u662f\u5426\u5305\u542bRFC 4034\u7b2c4\u7bc0\u5167\u898f\u5b9a\u7684\u8cc7\u6e90\u8a18\u9304\u3002<\/p>\n<p>\u76e3\u8996\u50b3\u5165\u7684DNS\u56de\u61c9\u6d41\u91cf\u4e26\u5075\u6e2c\u61c9\u7b54\u5340\u584a\u5167\u7684DNS\u8cc7\u6e90\u7d00\u9304\u662f\u5426\u5305\u542b\u6307\u5b9a\u5728RFC 4034\u7b2c4\u7bc0\uff08\u5b9a\u7fa9\u4e86NSEC\u8cc7\u6e90\u7d00\u9304\uff09\u5167\u7684DNS\u548c\u7d00\u9304\u985e\u578b\u3002\u5982\u679c\u88e1\u9762\u7684\u4f4d\u5143\u5716\uff08bitmap\uff09\u88ab\u8655\u7406\u4e26\u5305\u542b\u865b\u64ec\u578b\u614b\uff08pseudo-type\uff09\u507d\u985e\u578b\uff0c\u5c31\u61c9\u8a72\u52a0\u4ee5\u5c01\u9396\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>@\u539f\u6587\u51fa\u8655\uff1a<a href=\"https:\/\/blog.trendmicro.com\/trendlabs-security-intelligence\/systemd-vulnerability-leads-to-denial-of-service-on-linux\/\">systemd Vulnerability Leads to Denial of Service on Linux<\/a> \u4f5c\u8005\uff1a<a href=\"https:\/\/blog.trendmicro.com\/trendlabs-security-intelligence\/author\/williamsanchez\/\">William Gamazo Sanchez\uff08\u6f0f\u6d1e\u7814\u7a76\uff09<\/a><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8a31\u591aLinux\u767c\u884c\u7248\u90fd\u56e0\u70ba\u6700\u8fd1\u88ab\u62ab\u9732\u7684systemd\u7684\u6f0f\u6d1e\u800c\u9762\u81e8\u5371\u96aa\uff1aDNS\u89e3\u6790\u670d\u52d9\u7684\u4e00\u500b\u6f0f\u6d1e\u53ef\u80fd\u8b93\u7cfb\u7d71\u906d\u53d7\u5206 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_wpscppro_dont_share_socialmedia":false,"_wpscppro_custom_social_share_image":0,"_facebook_share_type":"","_twitter_share_type":"","_linkedin_share_type":"","_pinterest_share_type":"","_linkedin_share_type_page":"","_instagram_share_type":"","_medium_share_type":"","_threads_share_type":"","_google_business_share_type":"","_selected_social_profile":[],"_wpsp_enable_custom_social_template":false,"_wpsp_social_scheduling":{"enabled":false,"datetime":null,"platforms":[],"status":"template_only","dateOption":"today","timeOption":"now","customDays":"","customHours":"","customDate":"","customTime":"","schedulingType":"absolute"},"_wpsp_active_default_template":true},"categories":[156],"tags":[333,1759,3607,452,1173],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=\/wp\/v2\/posts\/53507"}],"collection":[{"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=53507"}],"version-history":[{"count":0,"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=\/wp\/v2\/posts\/53507\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=53507"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=53507"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.trendmicro.com.tw\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=53507"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}