Heap-based buffer overflow the "Answering Service" function in ICQ 2003b Build 3916 allows local users to cause a denial of service (application crash) via a long string in the "AwayMsg Presets" value in the ICQ\ICQPro\DefaultPrefs\Presets registry key.

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.

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

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.