The Cascading Style Sheets (CSS) implementation in Opera before 11.11 does not properly handle the column-count property, which allows remote attackers to cause a denial of service (infinite repaint loop and application hang) via a web page, as demonstrated by an unspecified Wikipedia page.

The remote host is affected by the vulnerability described in GLSA-201206-03 (Opera: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Opera. Please review       the CVE identifiers referenced below for details.
  Impact :

    A remote attacker could entice a user to open a specially crafted web       page, possibly resulting in execution of arbitrary code with the       privileges of the process or a Denial of Service condition. A remote       attacker may be able to: trick users into downloading and executing       arbitrary files, bypass intended access restrictions, spoof trusted       content, spoof URLs, bypass the Same Origin Policy, obtain sensitive       information, force subscriptions to arbitrary feeds, bypass the popup       blocker, bypass CSS filtering, conduct cross-site scripting attacks, or       have other unknown impact.
    A local attacker could perform symlink attacks to overwrite arbitrary       files with the privileges of the user running the application or possibly       obtain sensitive information.
    A physically proximate attacker may be able to access an email account.
  Workaround :

    There is no known workaround at this time.

The remote host is running the Opera web browser. 

Versions of Opera earlier than 11.11 are potentially affected by multiple vulnerabilities.  An attacker could craft a web page that will trigger the vulnerability which may allow arbitrary code execution subject to the privileges of the user running the affected application. (CVE-2011-2628)
 - Several errors exist that can cause application crashes. Affected items or functionality include unspecified web content, reloading pages after opening a pop-up from the Easy Sticky Note extension, handling of the column-count CSS property, destruction of a Silverlight instance, the handling of Certificate Revocation Lists (CRL). (CVE-2011-2629, CVE-2011-2630, CVE-2011-2631, CVE-2011-2632, CVE-2011-2633).

The version of Opera installed on the remote Windows host is earlier than 11.11. Such versions are potentially affected by:

  - A memory corruption vulnerability exists. The     application does not properly handle specific     framesets when unloading a page. An attacker could     craft a web page that will trigger the vulnerability     which may allow arbitrary code execution.
    (CVE-2011-2628)

  - Several errors exist that can cause application     crashes. Affected items or functionality include     unspecified web content, reloading pages after opening     a pop-up from the Easy Sticky Note extension, handling     of the column-count CSS property, destruction of a     Silverlight instance, the handling of Certificate     Revocation Lists (CRL). (CVE-2011-2629, CVE-2011-2630,     CVE-2011-2631, CVE-2011-2632, CVE-2011-2633).

ID	Name	Product	Family	Type	Severity
59631	GLSA-201206-03 : Opera: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	Local	critical
5925	Opera < 11.11 Multiple Vulnerabilities	Nessus Network Monitor	Web Clients		high
54587	Opera < 11.11 Multiple Vulnerabilities	Nessus	Windows	Local	high

Detections

Analytics

CVE-2011-2631

high

Tenable Plugins

critical

high

high