SeaMonkey is an open source Web browser, email and newsgroup client, IRC chat client, and HTML editor. A flaw was found in the way SeaMonkey creates temporary file names for downloaded files. If a local attacker knows the name of a file SeaMonkey is going to download, they can replace the contents of that file with arbitrary contents. A heap-based buffer overflow flaw was found in the SeaMonkey string to floating point conversion routines. A web page containing malicious JavaScript could crash SeaMonkey or, potentially, execute arbitrary code with the privileges of the user running SeaMonkey. A flaw was found in the way SeaMonkey handles text selection. A malicious website may be able to read highlighted text in a different domain , bypassing the same-origin policy. A flaw was found in the way SeaMonkey displays a right-to-left override character when downloading a file. In these cases, the name displayed in the title bar differs from the name displayed in the dialog body. An attacker could use this flaw to trick a user into downloading a file that has a file name or extension that differs from what the user expected. Several flaws were found in the processing of malformed web content. A web page containing malicious content could cause SeaMonkey to crash or, potentially, execute arbitrary code with the privileges of the user running SeaMonkey. All SeaMonkey users should upgrade to these updated packages, which correct these issues. After installing the update, SeaMonkey must be restarted for the changes to take effect.