AOL Instant Messenger prior to v5.5.3415 contains a buffer overflow in the CCertsByUserName::Cleanup() function which can lead to remote code execution. Can be exploited via HTML web pages or email via long aim: URIs. Fix available here.
658bc232448de8aa479f016c69377dec0c4df2e3dc1edc3e917f281631ca4178
TITLE:
AOL Instant Messenger File Transfer Error Message Buffer Overflow
Vulnerability
SECUNIA ADVISORY ID:
SA10021
VERIFY ADVISORY:
http://www.secunia.com/advisories/10021/
CRITICAL:
Moderately critical
IMPACT:
DoS, System access
WHERE:
From remote
SOFTWARE:
AOL Instant Messenger 5.x
DESCRIPTION:
A vulnerability has been identified in AOL Instant Messenger (AIM),
which potentially can be exploited by malicious people to compromise
a user's system.
The vulnerability is caused due to a boundary error in the
"CCertsByUserName::Cleanup()" function in "AimSecondarySvcs.dll" when
constructing certain error messages. The problem is that a
"sprintf()" function is used insecurely when constructing an error
message to inform the user that the connection with a specified user
was unsuccessful.
This can be exploited via a user's browser by constructing a
specially crafted link that uses the "aim:" URI handler and requests
a "getfile" operation, which supplies an overly long, specially
crafted string to the "screenname" parameter.
Example:
aim:getfile?screenname=AAA...[x1130]...AAA
Successful exploitation causes a buffer overflow and may potentially
allow execution of arbitrary code. However, it requires the
following:
1) A user has to be tricked into visiting a malicious website or
clicking a specially crafted link.
2) The user clicks "OK" when an anti-virus warning dialog box pops up
unless it has been disabled previously.
The vulnerability has been confirmed in version 5.2.3292 for Windows.
However, other versions may also be affected.
SOLUTION:
The vulnerability has been fixed in the latest beta (version 5.5.3415
Beta).
http://www.aim.com/get_aim/win/win_beta.adp
REPORTED BY / CREDITS:
AngryB, Digital Pranksters.
ORIGINAL ADVISORY:
Buffer Overflow in AOL Instant Messager's screenname parameter of
getfile:
http://www.digitalpranksters.com/advisories/aol/AIMProtocolBO.html
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