CVE-2012-3557
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 11.65 does not properly restrict the reading of JSON strings, which allows remote attackers to perform cross-domain loading of JSON resources and consequently obtain sensitive information via a crafted web site.
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 11.65 contains a Same-Origin Policy bypass vulnerability where the browser does not properly restrict the reading of JSON strings across different domains. This allows a malicious website to make cross-domain requests to load JSON resources from other domains and exfiltrate sensitive information that the attacker should not have access to.
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<= 11.62= 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
- Partial
- Integrity
- None
- Availability
- None
AV:N/AC:L/Au:N/C:P/I:N/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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Identify Opera browser versionOpen Opera and navigate to opera://about, or go to Help > About Opera. The version number is displayed on this page.Affected if The displayed version is 11.62 or lower, or falls within versions 5.0 through 6.04 listed in the affected range.
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Confirm Opera is the active browserVerify that Opera is the primary browser being used in the environment. Check running processes or installed programs for opera.exe.Affected if Opera browser is actively in use on the system.
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Check if cross-domain JSON requests are possibleThis vulnerability is inherent to the browser's handling of JSON responses across origins. No specific configuration check is needed - the flaw exists in how Opera processes JSON from different domains by default.Affected if Any version of Opera matching the affected ranges (5.0-6.04, 5.0-5.12, or 11.62 and below) is in use.
If Opera browser version is 11.62 or lower, or any version from 5.0 through 6.04, the environment is vulnerable to cross-domain JSON exfiltration attacks.
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 11.65 or later to patch the vulnerability. If Opera is no longer maintained in the environment, migrate to a supported browser.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2012-3557 — 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-2012-3557 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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