Microsoft Internet Explorer 6.0, when handling an expired CA-CERT in a webserver's certificate chain during a SSL/TLS handshake, does not prompt the user before searching for and finding a newer certificate, which may allow attackers to perform a man-in-the-middle attack. NOTE: it is not clear whether this poses a vulnerability.

Microsoft Internet Explorer 5.0 through 6.0 allows remote attackers to cause a denial of service (crash) via an object of type "text/html" with the DATA field that identifies the HTML document that contains the object, which may cause infinite recursion.

Internet Explorer 6.0 does not warn users when an expired certificate authority (CA) certificate is submitted to the user and a newer CA certificate is in the user's local repository, which could allow remote attackers to decrypt web sessions via a man-in-the-middle (MITM) attack.

Internet Explorer 5.5 and 6.0 allows remote attackers to bypass the cross-domain security model and access information on the local system or in other domains, and possibly execute code, via cached methods and objects, aka "Cross Domain Verification via Cached Methods."

Internet Explorer 5.01 through 6.0 does not properly perform security checks on certain encoded characters within a URL, which allows a remote attacker to steal potentially sensitive information from a user by redirecting the user to another site that has that information, aka "Encoded Characters Information Disclosure."

Internet Explorer 5.01 through 6.0 does not properly check certain parameters of a PNG file when opening it, which allows remote attackers to cause a denial of service (crash) by triggering a heap-based buffer overflow using invalid length codes during decompression, aka "Malformed PNG Image File Failure."

Heap-based buffer overflow in the Remote Data Services (RDS) component of Microsoft Data Access Components (MDAC) 2.1 through 2.6, and Internet Explorer 5.01 through 6.0, allows remote attackers to execute code via a malformed HTTP request to the Data Stub.

Microsoft Internet Explorer 4.0 through 6.0 could allow local users to differentiate between alphanumeric and non-alphanumeric characters used in a password by pressing certain control keys that jump between non-alphanumeric characters, which makes it easier to conduct a brute-force password guessing attack.

The Microsoft virtual machine (VM) in Internet Explorer 4.x and 5.x allows a remote attacker to read files via a malicious Java applet that escapes the Java sandbox, aka the "VM File Reading" vulnerability.

Vixie Cron on Linux systems allows local users to set parameters of sendmail commands via the MAILTO environmental variable.