Opera BrowserApplication · Opera

CVE-2011-4685

MEDIUM · 5.0 CVSS v2.0 Published 2011-12-07
Fix available
A fix is available. Upgrade to after 11.60 or later.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Dragonfly in Opera before 11.60 allows remote attackers to cause a denial of service (application crash) via unspecified content on a web page, as demonstrated by forbes.com.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The vulnerability exists in Opera's built-in Dragonfly developer tools before version 11.60. When a user visits a maliciously crafted webpage (as demonstrated on forbes.com), the Dragonfly component processes unspecified content that triggers an application crash, causing a denial of service.

MitigationUpgrade Opera to version 11.60 or later to patch the Dragonfly component, or use an alternative browser if Opera 11.x is required.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Opera BrowserApplication
Affected:<= 11.60= 5.0= 5.02= 5.10= 5.11= 5.12= 6.0= 6.1= 6.01= 6.02= 6.03= 6.04

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate Opera browser installation
    Search for opera.exe in common installation directories such as C:\Program Files\Opera or C:\Program Files (x86)\Opera on Windows, /Applications/Opera.app on macOS, or /usr/bin/opera on Linux. Use commands like 'where opera' (Windows), 'mdfind kMDItemCFBundleIdentifier == com.opera.Opera' (macOS), or 'which opera' (Linux).
    Affected if Opera browser is found installed on the system
  2. Determine installed Opera version
    Run Opera with version flags or check file properties. On Windows, right-click opera.exe and select Properties > Details to view File Version. From command line, run 'opera --version' or check Help > About Opera within the browser. On Linux, run 'opera -version'.
    Affected if The displayed version number matches any of the following: 5.0, 5.02, 5.10, 5.11, 5.12, 6.0, 6.1, 6.01, 6.02, 6.03, 6.04, or any version 11.60 and below
  3. Confirm Dragonfly component presence
    Dragonfly is built into Opera and is accessible via Tools > Advanced > Dragonfly, or by pressing Ctrl+Shift+I (Windows/Linux) or Cmd+Opt+I (macOS) while Opera is running. Attempt to access this developer tool to verify it exists.
    Affected if Dragonfly is present and accessible in the Opera installation, which is the case for all versions listed in the affected range
  4. Identify if Dragonfly was auto-launched or enabled
    Review Opera's configuration for automatic developer tool activation. Check opera:config for DeveloperToolsEnabled or similar settings. On affected versions, Dragonfly may be triggered automatically when visiting certain pages.
    Affected if Opera is configured to allow developer tool access or Dragonfly auto-initialization, which is the default behavior in vulnerable versions

A user is affected if Opera browser is installed with any version from 5.0 to 6.04, or version 11.60 and below, and the Dragonfly developer tool component is present and accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 11.60
Interim mitigation

Upgrade Opera to version 11.60 or later to patch the Dragonfly component, or use an alternative browser if Opera 11.x is required.

Fix this in Opera Browser Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2011-4685 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2011-4685 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data