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体验盒子Inshell Security Advisory
http://www.inshell.net
1. ADVISORY INFORMATION
-----------------------
Product:WinAmp
Vendor URL: www.winamp.com
Type: Pointer Issues [CWE-465]
Date found: 2013-06-05
Date published: 2013-07-01
CVSSv2 Score: 4,4 (AV:L/AC:M/Au:N/C:P/I:P/A:P)
CVE:CVE-2013-4695
2. CREDITS
----------
This vulnerability was discovered and researched by Julien Ahrens from
Inshell Security.
3. VERSIONS AFFECTED
--------------------
WinAmp v5.63, older versions may be affected too.
4. VULNERABILITY DESCRIPTION
----------------------------
An invalid pointer dereference vulnerability has been identified in
WinAmp v5.63.
The application loads the contents of the %APPDATA%\WinAmp\links.xml on
startup (the key lngId="default") and while browsing through the
bookmarks in the Browser view of the GUI, but does not properly validate
the length of the string loaded from the "<link name>" and "<home url>"
keys before using them in a pointer call in the library gen_ff.dll,
which leads to a invalid pointer dereference condition with possible
code execution.
An attacker needs to force the victim to place an arbitrary links.xml
file into the target directory in order to exploit the vulnerability.
Successful exploits can allow attackers to execute arbitrary code with
the privileges of the user running the application. Failed exploits will
result in a denial-of-service condition.
5. PROOF-OF-CONCEPT (DEBUG)
---------------------------
Registers:
EAX E85130FF
ECX 00430043 winamp.00430043
EDX 00D1F5B4
EBX 00000000
ESP 00D1F598
EBP 00D1F5C4
ESI 023D3170
EDI 7C80934A kernel32.GetTickCount
EIP 073D0EE1 gen_ff.073D0EE1
C 0ES 0023 32bit 0(FFFFFFFF)
P 1CS 001B 32bit 0(FFFFFFFF)
A 0SS 0023 32bit 0(FFFFFFFF)
Z 1DS 0023 32bit 0(FFFFFFFF)
S 0FS 003B 32bit 7FFDC000(FFF)
T 0GS 0000 NULL
D 0
O 0LastErr ERROR_SUCCESS (00000000)
EFL 00000246 (NO,NB,E,BE,NS,PE,GE,LE)
ST0 empty
ST1 empty
ST2 empty
ST3 empty
ST4 empty
ST5 empty
ST6 empty
ST7 empty
3 2 1 0E S P U O Z D I
FST 0000Cond 0 0 0 0Err 0 0 0 0 0 0 0 0(GT)
FCW 027FPrec NEAR,53Mask1 1 1 1 1 1
Stackview:
ESP-20 > 00000000
ESP-1C > 00000100
ESP-18 > 00C1F444
ESP-14 > 7C9215F9ntdll.7C9215F9
ESP-10 > 7C9215F9ntdll.7C9215F9
ESP-C> 00385D58
ESP-8> 00163700
ESP-4> 7C9215F9ntdll.7C9215F9
ESP ==>> 000000BE
ESP+4> 00D1F5B4
ESP+8> 00D1F5A8
ESP+C> 00000003
ESP+10 > 00D1F5C0
ESP+14 > 00D1F5BC
ESP+18 > 00D1F5B8
ESP+1C > 00D1FF14
ESP+20 > 00000900
Vulnerable code part (<link name>):
.text:07363F47 pushebp
.text:07363F48 mov ebp, esp
.text:07363F4A pushecx
.text:07363F4B push1
.text:07363F4D lea edx, [ebp+var_4]
.text:07363F50 pushedx
.text:07363F51 lea eax, [ebp+arg_4]
.text:07363F54 push0
.text:07363F56 push[ebp+arg_0]
.text:07363F59 mov [ebp+var_4], eax
.text:07363F5C mov eax, [ecx]
.text:07363F5E calldword ptr [eax]
.text:07363F60 leave
.text:07363F61 retn8
Vulnerable code part (<home url>):
.text:073620F8 pushebp
.text:073620F9 mov ebp, esp
.text:073620FB mov eax, [ecx]
.text:073620FD push0
.text:073620FF push0
.text:07362101 lea edx, [ebp+arg_0]
.text:07362104 pushedx
.text:07362105 push[ebp+arg_0]
.text:07362108 calldword ptr [eax]
.text:0736210A testeax, eax
.text:0736210C mov eax, [ebp+arg_0]
.text:0736210F jnz short loc_7362114
.text:07362111 mov eax, [ebp+arg_4]
.text:07362114
.text:07362114 loc_7362114:; CODE XREF:
sub_73620F8+17j
.text:07362114 pop ebp
.text:07362115 retn8
6. SOLUTION
-----------
Update to latest version v5.64 or newer.
7. REPORT TIMELINE
------------------
2013-06-05: Discovery of the vulnerability
2013-06-06: Vendor acknowledgement of the issue
2013-06-11: Vendor provides custom build that includes a fix
2013-06-12: The issue is still exploitable
2013-06-12: Provided another PoC to clarify the way to exploit
2013-06-13: Vendor provides custom build that includes a fix
2013-06-14: Confirmation that the issue is fixed
2013-06-19: Vendor releases v5.64 which includes the fix
2013-07-01: Coordinated Disclosure
8. REFERENCES
-------------
http://security.inshell.net
http://forums.winamp.com/showthread.php?t=364291
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