Contributor-level stored XSS via unescaped block classes
Published Feb 13, 2023 · Updated Mar 21, 2025
Stored XSS in RebelCode Spotlight Social Feeds before 1.4.3 allows remote authenticated users to execute JavaScript through block options. The Gutenberg block writes the Additional CSS class(es) option into embedded page markup without validation or output escaping, allowing an injected event handler to persist. Contributor-level access and a connected Instagram feed are required; the script runs when another user interacts with the affected page.
Summary
What happened
Stored XSS in RebelCode Spotlight Social Feeds before 1.4.3 allows remote authenticated users to execute JavaScript through block options. The Gutenberg block writes the Additional CSS class(es) option into embedded page markup without validation or output escaping, allowing an injected event handler to persist. Contributor-level access and a connected Instagram feed are required; the script runs when another user interacts with the affected page.
The record
- CVE
- CVE-2023-0379
- Published
- Feb 13, 2023
- Updated
- Mar 21, 2025
- Vendor
- RebelCode
- Product
- Spotlight Social Feeds
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 13, 2023CVE publishedPublication date reported by the CVE source.
- Mar 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.4.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Additional CSS class event-handler injection proof of conceptproof of concept · validated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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