Opera 7.54 and earlier on Gentoo Linux uses an insecure path for plugins, which could allow local users to gain privileges by inserting malicious libraries into the PORTAGE_TMPDIR (portage) temporary directory.
The International Domain Name (IDN) support in Firefox 1.0, Camino .8.5, and Mozilla before 1.7.6 allows remote attackers to spoof domain names using punycode encoded domain names that are decoded in URLs and SSL certificates in a way that uses homograph characters from other character sets, which facilitates phishing attacks.
Opera 7.54 and earlier does not properly validate base64 encoded binary data in a data: (RFC 2397) URL, which causes the URL to be obscured in a download dialog, which may allow remote attackers to trick users into executing arbitrary code.
Opera 7.54 allows remote attackers to cause a denial of service (application crash from memory exhaustion), as demonstrated using Javascript code that continuously creates nested arrays and then sorts the newly created arrays.
Opera 7.54 and earlier does not properly limit an applet's access to internal Java packages from Sun, which allows remote attackers to gain sensitive information, such as user names and the installation directory.
Opera 7.54 and earlier allows remote attackers to spoof file types in the download dialog via dots and non-breaking spaces (ASCII character code 160) in the (1) Content-Disposition or (2) Content-Type headers.
Opera 7.54 and earlier uses kfmclient exec to handle unknown MIME types, which allows remote attackers to execute arbitrary code via a shortcut or launcher that contains an Exec entry.
The Javascript engine in Opera 7.23 allows remote attackers to cause a denial of service (crash) by creating a new Array object with a large size value, then writing into that array.
Opera Browser 7.23, and other versions before 7.50, updates the address bar as soon as the user clicks a link, which allows remote attackers to redirect to other sites via the onUnload attribute.
A race condition in Opera web browser 7.53 Build 3850 causes Opera to fill in the address bar before the page has been loaded, which allows remote attackers to spoof the URL in the address bar via the window.open and location.replace HTML parameters, which facilitates phishing attacks.