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, possibly before 9.25, uses the HTTP Host header to determine the context of a document provided in a (1) 4xx or (2) 5xx CONNECT response from a proxy server, which allows man-in-the-middle attackers to execute arbitrary web script by modifying this CONNECT response, aka an "SSL tampering" attack.

Opera, possibly before 9.25, processes a 3xx HTTP CONNECT response before a successful SSL handshake, which allows man-in-the-middle attackers to execute arbitrary web script, in an https site's context, by modifying this CONNECT response to specify a 302 redirect to an arbitrary https web site.

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."

Opera displays a cached certificate for a (1) 4xx or (2) 5xx CONNECT response page returned by a proxy server, which allows man-in-the-middle attackers to spoof an arbitrary https site by letting a browser obtain a valid certificate from this site during one request, and then sending the browser a crafted 502 response page upon a subsequent request.

Opera executes DOM calls in response to a javascript: URI in the target attribute of a submit element within a form contained in an inline PDF file, which might allow remote attackers to bypass intended Adobe Acrobat JavaScript restrictions on accessing the document object, as demonstrated by a web site that permits PDF uploads by untrusted users, and therefore has a shared document.domain between the web site and this javascript: URI. NOTE: the researcher reports that Adobe's position is "a PDF file is active content."

Opera 9.64 allows remote attackers to cause a denial of service (application crash) via an XML document containing a long series of start-tags with no corresponding end-tags. NOTE: it was later reported that 9.52 is also affected.

Unspecified vulnerability in Opera before 9.64 has unknown impact and attack vectors, related to a "moderately severe issue."

Opera before 9.64 allows remote attackers to execute arbitrary code via a crafted JPEG image that triggers memory corruption.