Administrator-session script execution via echoed page parameter
Published Nov 1, 2021 · Updated Mar 31, 2025
Reflected XSS in NextScripts Social Networks Auto-Poster 4.3.20 and earlier allows remote attackers to run script in an administrator's browser. The column_post_title function in inc/nxs_class_snap.php inserts the POST-preferred $_REQUEST page value into action links without output escaping, while WordPress routes the page using the benign GET value. Exploitation requires a logged-in administrator to visit a self-submitting form; the resulting script runs in that session and can create administrators or install a backdoor.
Summary
What happened
Reflected XSS in NextScripts Social Networks Auto-Poster 4.3.20 and earlier allows remote attackers to run script in an administrator's browser. The column_post_title function in inc/nxs_class_snap.php inserts the POST-preferred $_REQUEST page value into action links without output escaping, while WordPress routes the page using the benign GET value. Exploitation requires a logged-in administrator to visit a self-submitting form; the resulting script runs in that session and can create administrators or install a backdoor.
The record
- CVE
- CVE-2021-38356
- Published
- Nov 1, 2021
- Updated
- Mar 31, 2025
- Vendor
- NextScripts Corp
- Product
- NextScripts: Social Networks Auto-Poster
- Classifications
- CWE-79, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 1, 2021CVE publishedPublication date reported by the CVE source.
- Mar 31, 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=4.3.20 <=4.3.20
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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