{"id":703,"date":"2016-02-19T05:42:40","date_gmt":"2016-02-19T05:42:40","guid":{"rendered":"http:\/\/www.selinuxplus.com\/?p=703"},"modified":"2016-02-19T05:48:05","modified_gmt":"2016-02-19T05:48:05","slug":"glibc-cve-2015-7547-%e6%bc%8f%e6%b4%9e","status":"publish","type":"post","link":"http:\/\/www.selinuxplus.com\/?p=703","title":{"rendered":"glibc CVE-2015-7547 \u6f0f\u6d1e"},"content":{"rendered":"<p>\u5f00\u6e90\u5b89\u5168\u7814\u7a76\u56e2\u961f\u62ab\u9732\u4e86Glibc getaddrinfo\u6ea2\u51fa\u6f0f\u6d1e\uff0c\u8be5\u6f0f\u6d1e\u5f71\u54cd\u8303\u56f4\u8f83\u5927\uff0c\u6d89\u53ca\u5f53\u524d\u4e3b\u8981\u7684Linux\u53d1\u884c\u7248\u3002\u636eGoogle \u535a\u5ba2\u4e2d\u6240\u8ff0\uff0c\u8be5\u6f0f\u6d1e\u5e94\u8be5\u662f\u53ef\u4ee5\u7ed5\u8fc7\u5185\u5b58\u9632\u62a4\u6280\u672f\uff0c\u4ece\u800c\u5f62\u6210\u4ee3\u7801\u6267\u884c\u6f0f\u6d1e\u3002<br \/>\n\u4ee5\u4e0b\u7248\u672c\u5747\u53d7\u5f71\u54cd<\/p>\n<pre class=\"lang:default decode:true \" >Red Hat Enterprise Linux Server 7 \r\nRed Hat Enterprise Linux Server 6 \r\nCentOS Linux 7 \r\nCentOS Linux 6 \r\nDebian Linux 6 squeeze \r\nDebian Linux 7 wheezy \r\nDebian Linux 8 jessie \r\nUbuntu Linux 15.10 \r\nUbuntu Linux 14.04 LTS \r\nUbuntu Linux 12.04 LTS<\/pre>\n<p>\u6f0f\u6d1e\u5371\u5bb3<br \/>\nGlibc\u7ec4\u4ef6\u5305\u542b\u4e86\u5927\u91cf\u6807\u51c6\u5e93\uff0c\u8fd9\u4e9b\u6807\u51c6\u5e93\u4f1a\u88ab\u4f17\u591a\u7684\u7a0b\u5e8f\u8c03\u7528\u3002\u5176\u4e2d libresolv\u5e93\u7528\u6765\u5b9e\u73b0\u4e3b\u673a\u540d\u4e0eIP\u5730\u5740\u4e4b\u95f4\u8f6c\u6362\u7684\u529f\u80fd\u3002\u4f5c\u4e3aglibc\u5305\u542b\u7684\u7ec4\u4ef6\u4e4b\u4e00\uff0cnss_dns\u6a21\u5757\u901a\u8fc7libresolv\u5e93\u8fdb\u884cDNS\u67e5\u8be2\uff0c\u4ece\u800c\u5b9e\u73b0Name Service Switch(NSS)\u670d\u52a1\u3002<br \/>\nLibresolv\u5e93\u4e2d\u7684\u4ee3\u7801\u5728\u6267\u884cA\/AAAA \u53cc\u91cdDNS\u67e5\u8be2\u65f6\u4f1a\u89e6\u53d1\u57fa\u4e8e\u5806\u6808\u7684\u7f13\u51b2\u533a\u6ea2\u51fa\u6f0f\u6d1e\u3002\u8fdc\u7a0b\u653b\u51fb\u8005\u53ef\u4ee5\u901a\u8fc7\u521b\u5efa\u7279\u6b8a\u7684DNS\u54cd\u5e94\uff0c\u9020\u6210libresolv\u5d29\u6e83\u6216\u6709\u53ef\u80fd\u4ee5\u8fd0\u884c\u5e93\u7528\u6237\u7684\u8eab\u4efd\u548c\u6743\u9650\u6267\u884c\u4ee3\u7801\uff1b\u8c03\u7528\u51fd\u6570send_dg\uff08UDP\u67e5\u8be2\uff09\u548csend_vc\uff08TCP\u67e5\u8be2\uff09\u65f6\u4f1a\u89e6\u53d1\u7f13\u51b2\u533a\u6ea2\u51fa\u3002<br \/>\n\u6f0f\u6d1e\u5206\u6790<br \/>\n\u901a\u8fc7\u5bf9\u5b89\u5168\u6f0f\u6d1e\u8fdb\u884c\u5206\u6790\uff0cglibc\u901a\u8fc7alloca\u51fd\u6570\u5728\u5806\u6808\u4e2d\u4fdd\u67092048\u5b57\u8282\u3002\u54cd\u5e94DNS\u67e5\u8be2\u8bf7\u6c42\u7684\u51fd\u6570\u4e3a_nss_dns_gethostbyname4_r\uff0c\u7136\u540e\u7ee7\u7eed\u8c03\u7528send_dg\u548csend_vc\u4e24\u4e2a\u51fd\u6570\u3002\u5982\u679c\u54cd\u5e94\u5927\u4e8e2048\u5b57\u8282\uff0c\u5c31\u4f1a\u4ece\u5806\u6808\u5206\u914d\u4e00\u4e2a\u65b0\u7684\u7f13\u51b2\u533a\u5e76\u66f4\u65b0\u6240\u6709\u7684\u4fe1\u606f\uff0c\u5305\u62ec\u7f13\u51b2\u533a\u6307\u9488\u3001\u65b0\u7684\u7f13\u51b2\u533a\u5927\u5c0f\u548c\u54cd\u5e94\u5305\u5927\u5c0f\u3002\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u8fd9\u4e00\u8fc7\u7a0b\u4f1a\u9020\u6210\u5806\u6808\u7f13\u51b2\u4e4b\u95f4\u7684\u4e0d\u5339\u914d\uff0c\u5e76\u4f1a\u518d\u6b21\u5206\u914d\u65b0\u7684\u5806\u6808\u3002\u6700\u7ec8\u5bfc\u81f4\u5806\u6808\u7f13\u51b2\u5c06\u5168\u90e8\u88ab\u7528\u4e8e\u5b58\u50a8DNS\u54cd\u5e94\uff0c\u6240\u4ee5\u8be5\u884c\u4e3a\u4f1a\u5bfc\u81f4\u5806\u6808\u7f13\u51b2\u7684\u6ea2\u51fa\u3002<br \/>\n\u9a8c\u8bc1\u65b9\u6cd5<\/p>\n<pre class=\"lang:default decode:true \" >[root@qfong CVE-2015-7547]# ldd --version\r\nldd (GNU libc) 2.17<\/pre>\n<p>DNS \u89e3\u6790\u4e3a 127.0.0.1<\/p>\n<pre class=\"lang:default decode:true \" >\/etc\/solv.conf\r\nnameserver 127.0.0.1 \r\ncat \/etc\/nsswitch.conf\r\nhosts:      dns files<\/pre>\n<p>1 \u91cd\u542f\u670d\u52a1<\/p>\n<pre class=\"lang:default decode:true \" >[root@qfong CVE-2015-7547]# systemctl restart nscd<\/pre>\n<p>2 \u6267\u884c\u64cd\u4f5c<\/p>\n<pre class=\"lang:default decode:true \" >[root@qfong CVE-2015-7547]# .\/CVE-2015-7547-poc.py \r\n[UDP] Total Data len recv 27\r\n[UDP] Total Data len recv 27\r\nConnected with 127.0.0.1:51780\r\n[TCP] Total Data len recv 58\r\n[TCP] Request1 len recv 27\r\n[TCP] Request2 len recv 27\r\n[UDP] Total Data len recv 27\r\n[UDP] Total Data len recv 27\r\nConnected with 127.0.0.1:51791\r\n[TCP] Total Data len recv 29<\/pre>\n<p>\u53e6\u4e00\u4e2a\u7ec8\u7aef\u6267\u884c.\/CVE-2015-7547-client \uff0c\u82e5\u542b\u6709\u6f0f\u6d1e\uff0c\u4f1a\u9020\u6210Segmentation Fault\u3002<\/p>\n<pre class=\"lang:default decode:true \" >[root@qfong CVE-2015-7547]# .\/CVE-2015-7547-client \r\nSegmentation fault (core dumped)\r\n<\/pre>\n<p>\u91c7\u53d6\u63aa\u65bd\uff1a<br \/>\nel7 \u66f4\u65b0\u5730\u5740 <\/p>\n<pre class=\"lang:default decode:true \" > http:\/\/mirror.centos.org\/centos\/7\/updates\/x86_64\/Packages\/glibc-2.17-106.el7_2.4.x86_64.rpm<\/pre>\n<p>el6 \u66f4\u65b0\u5730\u5740 <\/p>\n<pre class=\"lang:default decode:true \" > http:\/\/mirror.centos.org\/centos\/6\/updates\/<\/pre>\n<p>\u53c2\u8003\uff1a <\/p>\n<pre class=\"lang:default decode:true \" >https:\/\/www.exploit-db.com\/exploits\/39454\/\r\nhttps:\/\/access.redhat.com\/articles\/2161461\r\n<\/pre>\n<p>\u5347\u7ea7\u540e\uff1a\u4f7f\u7528 <\/p>\n<pre class=\"lang:default decode:true \" >lsof +c0 -d DEL | awk 'NR==1 || \/libc-\/ {print $2,$1,$4,$NF}' | column -t<\/pre>\n<p> \u67e5\u770b\u662f\u5426\u4f7f\u7528\u65b0\u7684glibc\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5f00\u6e90\u5b89\u5168\u7814\u7a76\u56e2\u961f\u62ab\u9732\u4e86Glibc getaddri&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4,103,5],"tags":[157,158,150],"_links":{"self":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts\/703"}],"collection":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=703"}],"version-history":[{"count":4,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts\/703\/revisions"}],"predecessor-version":[{"id":707,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=\/wp\/v2\/posts\/703\/revisions\/707"}],"wp:attachment":[{"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=703"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=703"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.selinuxplus.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}