Opera before 10.61 does not properly suppress clicks on download dialogs that became visible after a recent tab change, which allows remote attackers to conduct clickjacking attacks, and consequently execute arbitrary code, via vectors involving (1) closing a tab or (2) hiding a tab, a related issue to CVE-2005-2407.

Opera before 10.54 on Windows and Mac OS X does not properly enforce permission requirements for widget filesystem access and directory selection, which allows user-assisted remote attackers to create or modify arbitrary files, and consequently execute arbitrary code, via widget File I/O operations.

Cross-site scripting (XSS) vulnerability in Opera before 10.54 on Windows and Mac OS X, and before 10.11 on UNIX platforms, allows remote attackers to inject arbitrary web script or HTML via a data: URI, related to incorrect detection of the "opening site."

Opera before 10.54 on Windows and Mac OS X, and before 10.60 on UNIX platforms, does not properly restrict access to the full pathname of a file selected for upload, which allows remote attackers to obtain potentially sensitive information via unspecified DOM manipulations.

Opera before 10.54 on Windows and Mac OS X, and before 10.60 on UNIX platforms, does not properly restrict certain uses of homograph characters in domain names, which makes it easier for remote attackers to spoof IDN domains via unspecified choices of characters.

Opera before 10.60 on Windows and Mac OS X does not properly prevent certain double-click operations from running a program located on a web site, which allows user-assisted remote attackers to execute arbitrary code via a crafted web page that bypasses a dialog.

Opera before 10.53 on Windows and Mac OS X does not properly handle a series of document modifications that occur asynchronously, which allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via JavaScript that writes <marquee> sequences in an infinite loop, leading to attempted use of uninitialized memory. NOTE: this might overlap CVE-2006-6955.

Opera before 10.10 permits cross-origin loading of CSS stylesheets even when the stylesheet download has an incorrect MIME type and the stylesheet document is malformed, which allows remote attackers to obtain sensitive information via a crafted document.

Opera before 10.01 on Windows does not prevent use of Web fonts in rendering the product's own user interface, which allows remote attackers to spoof the address field via a crafted web site.

Opera before 10.01 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted domain name.

Opera 9.52 and earlier allows remote attackers to cause a denial of service (CPU consumption) via a series of automatic submissions of a form containing a KEYGEN element, a related issue to CVE-2009-1828.

Opera 9.52 and earlier allows remote attackers to cause a denial of service (unusable browser) by calling the window.print function in a loop, aka a "printing DoS attack," possibly a related issue to CVE-2009-0821.

Opera before 10.00 on Linux, Solaris, and FreeBSD does not properly implement the "INPUT TYPE=file" functionality, which allows remote attackers to trick a user into uploading an unintended file via vectors involving a "dropped file."

Opera before 10.00 does not check all intermediate X.509 certificates for revocation, which makes it easier for remote SSL servers to bypass validation of the certificate chain via a revoked certificate.

Opera before 10.00 does not properly handle a (1) '\0' character or (2) invalid wildcard character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority.

Opera 9.52 and earlier, and 10.00 Beta 3 Build 1699, does not properly block data: URIs in Location headers in HTTP responses, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors related to (1) injecting a Location header that contains JavaScript sequences in a data:text/html URI or (2) entering a data:text/html URI with JavaScript sequences when specifying the content of a Location header. NOTE: the JavaScript executes outside of the context of the HTTP site.

Opera 9.52 and earlier allows remote attackers to cause a denial of service (CPU and memory consumption, and application hang) via a long Unicode string argument to the write method, a related issue to CVE-2009-2479.

Opera, possibly 9.64 and earlier, allows remote attackers to cause a denial of service (memory consumption) via a large integer value for the length property of a Select object, a related issue to CVE-2009-1692.

Opera 9.52 and earlier does not block javascript: URIs in Refresh headers in HTTP responses, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors related to (1) injecting a Refresh header or (2) specifying the content of a Refresh header, a related issue to CVE-2009-1312. NOTE: it was later reported that 10.00 Beta 3 Build 1699 is also affected.

Opera detects http content in https web pages only when the top-level frame uses https, which allows man-in-the-middle attackers to execute arbitrary web script, in an https site's context, by modifying an http page to include an https iframe that references a script file on an http site, related to "HTTP-Intended-but-HTTPS-Loadable (HPIHSL) pages."