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Mallory
MediumPublic exploit

XSS via unsafe postMessage() origin handling in Stockdio Historical Chart WordPress plugin (< 2.8.1)

IdentifiersCVE-2020-28707CWE-79· Improper Neutralization of Input…

The Stockdio Historical Chart WordPress plugin prior to 2.8.1 contains a cross-site scripting issue in stockdio_chart_historical-wp.js (wp-content/plugins/stockdio-historical-chart/assets/) due to unsafe handling of window.postMessage() events. The stockdio_eventer message handler does not validate the event.origin and only checks that e.data and e.data.method are not undefined before evaluating attacker-controlled content via eval(e.data.method). An attacker-controlled website can open a window to a vulnerable WordPress instance and send a crafted postMessage (e.g., postMessage(msg,'*')) to trigger execution of arbitrary JavaScript in the context of the vulnerable site.

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For your environment

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows arbitrary JavaScript execution in the context of the vulnerable WordPress site (DOM-based XSS), enabling actions such as session/token theft, performing authenticated actions as the victim user, content manipulation, and further client-side compromise depending on the victim’s privileges and browser context.

Mitigation

If you can’t patch tonight, do this now.

If immediate upgrading is not possible, reduce exposure by disabling/removing the plugin, and implement compensating controls such as a restrictive Content Security Policy (CSP) to limit script execution and reduce XSS impact. Additionally, ensure any postMessage handlers validate event.origin against an allowlist and avoid eval()-based dispatch patterns.

Remediation

Patch, then assume compromise.

Upgrade the Stockdio Historical Chart plugin to version 2.8.1 or later, where the postMessage handler behavior is corrected to prevent evaluation of untrusted message content and/or to enforce strict origin validation and safe message parsing/dispatch without eval().
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
StockdioStockdio Historical Chartapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

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Detection signatures

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Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

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