Opera before 57.0.3098.106 is vulnerable to a DLL Search Order hijacking attack where an attacker can send a ZIP archive composed of an HTML page along with a malicious DLL to the target. Once the document is opened, it may allow the attacker to take full control of the system from any location within the system. The issue lies in the loading of the shcore.dll and dcomp.dll files: these files are being searched for by the program in the same system-wide directory where the HTML file is executed.

Opera Mini 13 and Opera Stable 36 allow remote attackers to spoof the displayed URL via a crafted HTML document, related to the about:blank URL.

The TLS protocol 1.2 and earlier supports the rsafixeddh, dssfixeddh, rsafixedecdh, and ecdsafixedecdh values for ClientCertificateType but does not directly document the ability to compute the master secret in certain situations with a client secret key and server public key but not a server secret key, which makes it easier for man-in-the-middle attackers to spoof TLS servers by leveraging knowledge of the secret key for an arbitrary installed client X.509 certificate, aka the "Key Compromise Impersonation (KCI)" issue.

The HTTP/2 protocol does not consider the role of the TCP congestion window in providing information about content length, which makes it easier for remote attackers to obtain cleartext data by leveraging a web-browser configuration in which third-party cookies are sent, aka a "HEIST" attack.

The HTTPS protocol does not consider the role of the TCP congestion window in providing information about content length, which makes it easier for remote attackers to obtain cleartext data by leveraging a web-browser configuration in which third-party cookies are sent, aka a "HEIST" attack.

The Web Browser for Android (aka explore.web.browser) application 1.2 for Android does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

Cross-site scripting (XSS) vulnerability in Opera before 15.00 allows remote attackers to inject arbitrary web script or HTML by leveraging UTF-8 encoding.

Unspecified vulnerability in Opera before 12.15 has unknown impact and attack vectors, related to a "moderately severe issue."

Opera before 12.15 does not properly block top-level domains in Set-Cookie headers, which allows remote attackers to obtain sensitive information by leveraging control of a different web site in the same top-level domain.

Opera before 12.13 allows remote attackers to execute arbitrary code via crafted clipPaths in an SVG document.

Opera before 12.13 allows remote attackers to execute arbitrary code via vectors involving DOM events.

Opera before 12.13 does not send CORS preflight requests in all required cases, which allows remote attackers to bypass a CSRF protection mechanism via a crafted web site that triggers a CORS request.

Opera before 12.12 on UNIX uses weak permissions for the profile directory, which allows local users to obtain sensitive information by reading a (1) cache file, (2) password file, or (3) configuration file, or (4) possibly gain privileges by modifying or overwriting a configuration file.

Opera before 12.10 follows Internet shortcuts that are referenced by a (1) IMG element or (2) other inline element, which makes it easier for remote attackers to conduct phishing attacks via a crafted web site, as exploited in the wild in November 2012.

Opera before 11.67 and 12.x before 12.02 allows remote attackers to cause truncation of a dialog, and possibly trigger downloading and execution of arbitrary programs, via a crafted web site.

Opera before 12.12 does not properly allocate memory for GIF images, which allows remote attackers to execute arbitrary code or cause a denial of service (memory overwrite) via a malformed image.

Opera before 12.10 does not properly handle incorrect size data in a WebP image, which allows remote attackers to obtain potentially sensitive information from process memory by using a crafted image as the fill pattern for a canvas.

Heap-based buffer overflow in Opera before 12.11 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a long HTTP response.

Opera before 12.12 allows remote attackers to spoof the address field via a high rate of HTTP requests.

Opera before 12.11 allows remote attackers to determine the existence of arbitrary local files via vectors involving web script in an error page.

Opera before 12.10 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a malformed SVG image.

Untrusted search path vulnerability in Opera before 10.62 allows local users to gain privileges via a Trojan horse dwmapi.dll file in the current working directory, as demonstrated by a directory that contains a .htm, .mht, .mhtml, .xht, .xhtm, or .xhtl file. NOTE: some of these details are obtained from third party information.

Opera before 11.60 allows remote attackers to spoof the address bar via unspecified homograph characters, a different vulnerability than CVE-2010-2660.

Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, allows user-assisted remote attackers to trick users into downloading and executing arbitrary files via a small window for the download dialog, a different vulnerability than CVE-2012-1924.

Opera before 12.01 allows remote attackers to cause a denial of service (application crash) via a crafted web site, as demonstrated by the Lenovo "Shop now" page.

Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, does not properly escape characters in DOM elements, which makes it easier for remote attackers to bypass cross-site scripting (XSS) protection mechanisms via a crafted HTML document.

Unspecified vulnerability in Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, has unknown impact and attack vectors, related to a "low severity issue."

Opera before 11.65 does not ensure that keyboard sequences are associated with a visible window, which makes it easier for user-assisted remote attackers to conduct cross-site scripting (XSS) attacks or execute arbitrary code via a crafted web site, related to a "hidden keyboard navigation" issue.

Opera before 11.65 does not properly restrict the reading of JSON strings, which allows remote attackers to perform cross-domain loading of JSON resources and consequently obtain sensitive information via a crafted web site.