Opera » Opera Browser : Security Vulnerabilities, CVEs, CVSS score between 5 and 5.99

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 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.

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 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 10.10, 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 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.

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".

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).

Opera 7.50 and earlier allows remote web sites to provide a "Shortcut Icon" (favicon) that is wider than expected, which could allow the web sites to spoof a trusted domain and facilitate phishing attacks using a wide icon and extra spaces.

Opera does not prevent cookies that are sent over an insecure channel (HTTP) from also being sent over a secure channel (HTTPS/SSL) in the same domain, which could allow remote attackers to steal cookies and conduct unauthorized activities, aka "Cross Security Boundary Cookie Injection."

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 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.

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.

The International Domain Name (IDN) support in Opera 7.54 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.

The International Domain Name (IDN) support in Epiphany 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 8.01 allows remote attackers to cause a denial of service (CPU consumption) via a crafted JPEG image, as demonstrated using random.jpg.

Opera 8.01, when the "Arial Unicode MS" font (ARIALUNI.TTF) is installed, does not properly handle extended ASCII characters in the file download dialog box, which allows remote attackers to spoof file extensions and possibly trick users into executing arbitrary code.

The mail client in Opera before 8.50 opens attached files from the user's cache directory without warning the user, which might allow remote attackers to inject arbitrary web script and spoof attachment filenames.

Unspecified "drag-and-drop vulnerability" in Opera Web Browser before 8.50 on Windows allows "unintentional file uploads."

Opera Web Browser 8.50 and 8.0 through 8.0.2 allows remote attackers to spoof the URL in the status bar via the title in an image in a link to a trusted site within a form to the malicious site.