The ICQPhone.SipxPhoneManager ActiveX control in America Online ICQ 5.1 allows remote attackers to download and execute arbitrary code via the DownloadAgent function, as demonstrated using an ICQ avatar.

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.

Multiple cross-site scripting (XSS) vulnerabilities in the RSS Feed module in AOL ICQ Toolbar 1.3 for Internet Explorer (toolbaru.dll) allow remote attackers to process arbitrary web script or HTML in the Feeds interface context via the (1) title and (2) description elements within an item element in an RSS feed.

AOL ICQ Toolbar 1.3 for Internet Explorer (toolbaru.dll) does not properly validate the origin of the configuration web page (options2.html), which allows user-assisted remote attackers to provide a web page that contains disguised checkboxes that trick the user into reconfiguring the toolbar.

Heap-based buffer overflow in the MCRegEx__Search function in AOL ICQ Pro 2003b Build 3916 and earlier allows remote attackers to execute arbitrary code via an inconsistent length field of a Message in a 0x2711 Type-Length-Value (TLV) type.

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.

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.

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.

centericq 4.20.0-r3 with "Enable peer-to-peer communications" set allows remote attackers to cause a denial of service (segmentation fault and crash) via short zero-length packets, and possibly packets of length 1 or 2, as demonstrated using Nessus.

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.