Apple has released Security Update 2007-006.
You can get Security Update 2007-006 via Softwre Update or download it
here.
"Security Update 2007-006
WebCore
CVE-ID: CVE-2007-2401
Available for: Mac OS X v10.3.9, Mac OS X Server v10.3.9, Mac OS X v10.4.9 or later, Mac OS X Server v10.4.9 or later
Impact: Visiting a malicious website may allow cross-site requests
Description: An HTTP injection issue exists in XMLHttpRequest when serializing headers into an HTTP request. By enticing a user to visit a maliciously crafted web page, an attacker could conduct cross-site scripting attacks. This update addresses the issue by performing additional validation of header parameters. Credit to Richard Moore of Westpoint Ltd. for reporting this issue.
WebKit
CVE-ID: CVE-2007-2399
Available for: Mac OS X v10.3.9, Mac OS X Server v10.3.9, Mac OS X v10.4.9 or later, Mac OS X Server v10.4.9 or later
Impact: Visiting a maliciously crafted website may lead to an unexpected application termination or arbitrary code execution
Description: An invalid type conversion when rendering frame sets could lead to memory corruption. Visiting a maliciously crafted web page may lead to an unexpected application termination or arbitrary code execution. Credit to Rhys Kidd of Westnet for reporting this issue."