Opera Browser

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 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, 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 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 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 9.52 does not ensure that the address field of a news feed represents the feed's actual URL, which allows remote attackers to change this field to display the URL of a page containing web script controlled by the attacker.

Opera before 11.62 allows remote attackers to spoof the address field by triggering a page reload followed by a redirect to a different domain.

Opera before 11.62 allows remote attackers to spoof the address field by triggering the launch of a dialog window associated with a different domain.

Mozilla Firefox 2.0.0.1 allows remote attackers to bypass the Phishing Protection mechanism by adding certain characters to the end of the domain name, as demonstrated by the "." and "/" characters, which is not caught by the Phishing List blacklist filter.

The JavaScript engine in Opera before 11.60 does not properly implement the in operator, which allows remote attackers to bypass the Same Origin Policy via vectors related to variables on different web sites.

Opera before 11.62 on Mac OS X allows remote attackers to spoof the address field and security dialogs via crafted styling that causes page content to be displayed outside of the intended content area.

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.

Characters from languages are such as Arabic, Hebrew are displayed from RTL (Right To Left) order in Opera 37.0.2192.105088 for Android, due to mishandling of several unicode characters such as U+FE70, U+0622, U+0623 etc and how they are rendered combined with (first strong character) such as an IP address or alphabet could lead to a spoofed URL. It was noticed that by placing neutral characters such as "/", "?" in filepath causes the URL to be flipped and displayed from Right To Left. However, in order for the URL to be spoofed the URL must begin with an IP address followed by neutral characters as omnibox considers IP address to be combination of punctuation and numbers and since LTR (Left To Right) direction is not properly enforced, this causes the entire URL to be treated and rendered from RTL (Right To Left). However, it doesn't have be an IP address, what matters is that first strong character (generally, alphabetic character) in the URL must be an RTL character.

Opera before 10.10, when exception stacktraces are enabled, places scripting error messages from a web site into variables that can be read by a different web site, which allows remote attackers to obtain sensitive information or conduct cross-site scripting (XSS) attacks via unspecified vectors.

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 9.61 does not properly block scripts during preview of a news feed, which allows remote attackers to create arbitrary new feed subscriptions and read the contents of arbitrary feeds.

Visual truncation vulnerability in Opera 9.21 allows remote attackers to spoof the address bar and possibly conduct phishing attacks via a long hostname, which is truncated after 34 characters, as demonstrated by a phishing attack using HTTP Basic Authentication.

Opera cannot properly restrict modifications to cookies established in HTTPS sessions, which allows man-in-the-middle attackers to overwrite or delete arbitrary cookies via a Set-Cookie header in an HTTP response, related to lack of the HTTP Strict Transport Security (HSTS) includeSubDomains feature, aka a "cookie forcing" issue.

Opera before 9.63 does not properly 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.

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.

Integer signedness error in Opera before 8.54 allows remote attackers to execute arbitrary code via long values in a stylesheet attribute, which pass a length check. NOTE: a sign extension problem makes the attack easier with shorter strings.

Heap-based buffer overflow in Opera 9.0 and 9.01 allows remote attackers to execute arbitrary code via a long URL in a tag (long link address).

A design error in Opera 8.01 and earlier allows user-assisted attackers to execute arbitrary code by overlaying a malicious new window above a file download dialog box, then tricking the user into double-clicking on the "Run" button, aka "link hijacking".

AcroPDF.DLL in Adobe Reader 8.0, when accessed from Mozilla Firefox, Netscape, or Opera, allows remote attackers to cause a denial of service (unspecified resource consumption) via a .pdf URL with an anchor identifier that begins with search= followed by many %n sequences, a different vulnerability than CVE-2006-6027 and CVE-2006-6236.

Opera 9 allows remote attackers to cause a denial of service (crash) via an A tag with an href attribute with a URL containing a long hostname, which triggers an out-of-bounds operation.

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.

Opera 8.02 and earlier allows remote attackers to cause a denial of service (client crash) via (1) a crafted HTML file with a "content: url(0);" style attribute, a "bodyA" tag, a long string, and a "u" tag with a long attribute, as demonstrated by opera.html; and (2) a BGSOUND element with a "margin:-99;" STYLE attribute.

Opera 9 allows remote attackers to cause a denial of service (crash) via a crafted web page that triggers an out-of-bounds memory access, related to an iframe and JavaScript that accesses certain style sheets properties.

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 11.11 allows remote attackers to cause a denial of service (application crash) by setting the FACE attribute of a FONT element within an IFRAME element after changing the SRC attribute of this IFRAME element to an about:blank value.

Opera before 9.0 does not reset the SSL security bar after displaying a download dialog from an SSL-enabled website, which allows remote attackers to spoof a trusted SSL certificate from an untrusted website and 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 before 8.51, when running on Windows with Input Method Editor (IME) installed, allows remote attackers to cause a denial of service (persistent application crash) by bookmarking a site with a long title.

Opera 8.50 allows remote attackers to cause a denial of service (crash) via a Java applet with a large string argument to the removeMember JNI method for the com.opera.JSObject class.

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.

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 8.01 allows remote attackers to cause a denial of service (CPU consumption) via a crafted JPEG image, as demonstrated using random.jpg.

Opera before 7.54 allows remote attackers to modify properties and methods of the location object and execute Javascript to read arbitrary files from the client's local filesystem or display a false URL to the user.

Unspecified vulnerability in Opera before 9.5 allows remote attackers to spoof the contents of trusted frames on the same parent page by modifying the location, which can facilitate phishing attacks.

The CSS functionality in Opera 9 on Windows XP SP2 allows remote attackers to cause a denial of service (crash) by setting the background property of a DHTML element to a long http or https URL, which triggers memory corruption.