Codegate CTF 2019

签到题

base85一把梭

KingMaker

20000

给了20k个.so文件, 然后用一个程序去调用, 分类一波以后一共如下四种:

1. filter1
   过滤了;, *, |, &, $, `, >, <, r
2. filter2
   过滤了v, m, p, d, n, bin, sh, bash, f, l, g
3. test1

   memset(&buf, 0, 0x30uLL);
   v2 = 0;
   puts("This is lib_100 file.");
   puts("How do you find vulnerable file?");
   read(0, &buf, 0x32uLL);
   system("exit");

4. test2
   用filter1和filter2过滤后, 执行system(“ls \”input\”)

看起来似乎是命令注入