The ICQ Webserver allows remote attackers to use .. to access arbitrary files outside of the user's personal directory.

ICQ 98 beta on Windows NT leaks the internal IP address of a client in the TCP data segment of an ICQ packet instead of the public address (e.g. through NAT), which provides remote attackers with potentially sensitive information about the client or the internal network configuration.

ICQ99 ICQ web server build 1701 with "Active Homepage" enabled generates allows remote attackers to determine the existence of files on the server by comparing server responses when a file exists ("404 Forbidden") versus when a file does not exist ("404 not found").

Win32 ICQ 98a 1.30, and possibly other versions, does not display the entire portion of long filenames, which could allow attackers to send an executable file with a long name that contains so many spaces that the .exe extension is not displayed, which could make the user believe that the file is safe to open from the client.

Buffer overflow in ICQ 99b 1.1.1.1 client allows remote attackers to execute commands via a malformed URL within an ICQ message.

The guestbook CGI program in ICQ Web Front service for ICQ 2000a, 99b, and others allows remote attackers to cause a denial of service via a URL with a long name parameter.

ICQ Web Front HTTPd allows remote attackers to cause a denial of service by requesting a URL that contains a "?" character.

Mirabilis ICQ WebFront Plug-in ICQ2000b Build 3278 allows a remote attacker to create a denial of service via HTTP URL requests containing a large number of % characters.

ICQ 2001a Alpha and earlier allows remote attackers to automatically add arbitrary UINs to an ICQ user's contact list via a URL to a web page with a Content-Type of application/x-icq, which is processed by Internet Explorer.

Buffer overflow in ICQ before 2001B Beta v5.18 Build #3659 allows remote attackers to execute arbitrary code via a Voice Video & Games request.

ICQ 2001b Build 3659 allows remote attackers to cause a denial of service (crash) via a malformed picture that contains large height and width values, which causes the crash when viewed in Userdetails.

AOL ICQ 2002a Build 3722 allows remote attackers to cause a denial of service (crash) via a malformed .hpf file.

Buffer overflow in ICQ 2.6x for MacOS X 10.0 through 10.1.2 allows remote attackers to cause a denial of service and possibly execute arbitrary code via a long request.

ICQ 2001a and 2002b allows remote attackers to cause a denial of service (memory consumption and hang) via a contact message with a large contacts number.

ICQ client 2001b, 2002a and 2002b allows remote attackers to cause a denial of service (CPU consumption or crash) via a message with a large number of emoticons.

Format string vulnerability in POP3 client for Mirabilis ICQ Pro 2003a allows remote malicious servers to execute arbitrary code via format strings in the response to a UIDL command.

Integer signedness errors in the POP3 client for Mirabilis ICQ Pro 2003a allow remote attackers to execute arbitrary code via the (1) Subject or (2) Date headers.

The "ICQ Features on Demand" functionality for Mirabilis ICQ Pro 2003a does not properly verify the authenticity of software upgrades, which allows remote attackers to install arbitrary software via a spoofing attack.

The Message Session window in Mirabilis ICQ Pro 2003a allows remote attackers to cause a denial of service (CPU consumption) by spoofing the address of an ADS server and sending HTML with a -1 width in a table tag.

icqateimg32.dll parsing/rendering library in Mirabilis ICQ Pro 2003a allows remote attackers to cause a denial of service via malformed GIF89a headers that do not contain a GCT (Global Color Table) or an LCT (Local Color Table) after an Image Descriptor.

Cross-site scripting (XSS) vulnerability in the ICQ Web Front guestbook (guestbook.html) allows remote attackers to insert arbitrary web script and HTML via the message field.

Buffer overflow in Mirabilis ICQ 2003a allows user-assisted attackers to execute arbitrary code by convincing a user to enter long strings into the First Name and Last Name fields.

GUI display truncation vulnerability in ICQ Inc. (formerly Mirabilis) ICQ 2003a, 2003b, Lite 4.0, Lite 4.1, and possibly other Windows versions allows user-assisted remote attackers to hide malicious file extensions, bypass Windows security warnings via a filename that is all uppercase and of a specific length, which truncates the malicious extension from the display and could trick a user into executing arbitrary programs.

ICQ Inc. (formerly Mirabilis) ICQ 2003a, 2003b, Lite 4.0, Lite 4.1, and possibly other Windows versions allows user-assisted remote attackers to hide malicious file extensions and bypass Windows security warnings via a filename that ends in an assumed-safe extension such as JPG, and possibly containing other modified properties such as company name, icon, and description, which could trick a user into executing arbitrary programs.

Cross-Application Scripting (XAS) vulnerability in ICQ Client 5.04 build 2321 and earlier allows remote attackers to inject arbitrary web script from one application into another via a banner, which is processed in the My Computer zone using the Internet Explorer COM object.