The JavaScript garbage collector in WebKit in Apple Safari before 4.0, iPhone OS 1.0 through 2.2.1, and iPhone OS for iPod touch 1.1 through 2.2.1 does not properly handle allocation failures, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted HTML document that triggers write access to an "offset of a NULL pointer."

WebKit in Apple Safari before 4.0, iPhone OS 1.0 through 2.2.1, and iPhone OS for iPod touch 1.1 through 2.2.1 does not properly handle constant (aka const) declarations in a type-conversion operation during JavaScript exception handling, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted HTML document.

Cross-site scripting (XSS) vulnerability in WebKit in Apple Safari before 4.0, iPhone OS 1.0 through 2.2.1, and iPhone OS for iPod touch 1.1 through 2.2.1 allows remote attackers to inject arbitrary web script or HTML by overwriting the document.implementation property of (1) an embedded document or (2) a parent document.

Cross-site scripting (XSS) vulnerability in WebKit in Apple Safari before 4.0, iPhone OS 1.0 through 2.2.1, and iPhone OS for iPod touch 1.1 through 2.2.1 allows remote attackers to inject arbitrary web script or HTML via an event handler that triggers script execution in the context of the next loaded document.

Apple Safari before 4.0 does not properly check for revoked Extended Validation (EV) certificates, which makes it easier for remote attackers to trick a user into accepting an invalid certificate.

WebKit in Apple Safari before 4.0, iPhone OS 1.0 through 2.2.1, and iPhone OS for iPod touch 1.1 through 2.2.1 does not prevent web sites from loading third-party content into a subframe, which allows remote attackers to bypass the Same Origin Policy and conduct "clickjacking" attacks via a crafted HTML document.