CVE-2011-4681
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 · uneditedOpera before 11.60 does not properly consider the number of . (dot) characters that conventionally exist in domain names of different top-level domains, which allows remote attackers to bypass the Same Origin Policy by leveraging access to a different domain name in the same top-level domain, as demonstrated by the .no or .uk domain.
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 · high confidenceOpera before 11.60 had a flaw in its Same Origin Policy implementation where it incorrectly determined the base domain for certain TLDs like .no and .uk. This allowed a page on one subdomain (e.g., attacker.example.co.uk) to access content on a different subdomain (e.g., victim.example.co.uk) in the same TLD, bypassing the intended cross-origin restrictions.
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<= 11.60= 5.0= 5.02= 5.10= 5.11= 5.12= 6.0= 6.1= 6.01= 6.02= 6.03= 6.04CVSS 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
- Partial
- Availability
- None
AV:N/AC:L/Au:N/C:N/I:P/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Check if Opera browser is installedLook for Opera executable: on Windows check C:\Program Files\Opera\opera.exe or C:\Program Files (x86)\Opera\opera.exe; on Linux check /usr/bin/opera or /usr/local/bin/opera; on macOS check /Applications/Opera.appAffected if Opera is not installed on the system
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Determine installed Opera versionRun 'opera --version' from command line, or open Opera and go to Help > About Opera to view the version numberAffected if The version displayed is 11.60 or lower, or matches any of these: 5.0, 5.02, 5.10, 5.11, 5.12, 6.0, 6.1, 6.01, 6.02, 6.03, 6.04
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Identify if affected TLDs are in useReview web applications or websites hosted on subdomains of .no or .uk TLDs that the browser user interacts withAffected if The user accesses or hosts web content on subdomains under .no or .uk TLDs (e.g., example.co.uk, site.no)
User is affected if Opera version 11.60 or lower is installed AND the browser is used to access content on subdomains of .no or .uk TLDs, allowing potential cross-subdomain data access due to the Same Origin Policy bypass.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade Opera to version 11.60 or later to obtain the patch for this Same Origin Policy bypass vulnerability.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 h
- Review / QA1.0 h
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 locallyCheck whether your project pulls in CVE-2011-4681 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2011-4681 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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