Victim-browser script execution via unescaped redirect URL
Published Jun 23, 2021 · Updated Aug 4, 2024
Reflected XSS in GetSimpleCMS 3.3.15 and earlier allows remote attackers to execute script in a victim's browser via redirect_url. The changedata.php handler accepts redirectto without validation, and redirect() embeds the value inside a JavaScript string when headers_sent() is true. Exploitation requires victim interaction and the headers-already-sent path; successful script runs with the affected site's browser privileges.
Summary
What happened
Reflected XSS in GetSimpleCMS 3.3.15 and earlier allows remote attackers to execute script in a victim's browser via redirect_url. The changedata.php handler accepts redirectto without validation, and redirect() embeds the value inside a JavaScript string when headers_sent() is true. Exploitation requires victim interaction and the headers-already-sent path; successful script runs with the affected site's browser privileges.
The record
- CVE
- CVE-2020-18657
- Published
- Jun 23, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-79, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 23, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- GetSimpleCMS 3.3.15 limited reflected XSS disclosureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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