Microsoft Internet Explorer 5.1

Microsoft Internet Explorer 5.01 through 6 allows remote attackers to execute arbitrary code via HTML elements with a certain crafted tag, which leads to memory corruption.

Internet Explorer 5.1 for Macintosh allows remote attackers to bypass security checks and invoke local AppleScripts within a specific HTML element, aka the "Local Applescript Invocation" vulnerability.

Buffer overflow in various Microsoft applications for Macintosh allows remote attackers to cause a denial of service (crash) or execute arbitrary code by invoking the file:// directive with a large number of / characters, which affects Internet Explorer 5.1, Outlook Express 5.0 through 5.0.2, Entourage v. X and 2001, PowerPoint v. X, 2001, and 98, and Excel v. X and 2001 for Macintosh.

Internet Explorer 5.01 SP4 up to 6 on various Windows operating systems, including IE 6.0.2900.2180 on Windows XP, allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a web page with embedded CLSIDs that reference certain COM objects that are not ActiveX controls, as demonstrated using the JVIEW Profiler (Javaprxy.dll). NOTE: the researcher says that the vendor could not reproduce this problem.

Microsoft Internet Explorer 6.0.2900.2180 and earlier allows remote attackers to cause a denial of service (CPU and memory consumption) via a long Unicode string argument to the write method, a related issue to CVE-2009-2479. NOTE: it was later reported that 7.0.6000.16473 and earlier are also affected.