Stored XSS via unchecked upload MIME type
Published Aug 31, 2023 · Updated Oct 1, 2024
Stored XSS in InstantCMS 2 before 2.16.1-git allows remote authenticated users to run script in another user's browser via an upload. The cmsUploader upload path trusted a permitted filename extension without verifying the uploaded file's MIME type, allowing active content under an accepted extension. Low-privileged access and a victim viewing the stored upload are required; the script runs in the site's origin and can read or alter accessible data.
Summary
What happened
Stored XSS in InstantCMS 2 before 2.16.1-git allows remote authenticated users to run script in another user's browser via an upload. The cmsUploader upload path trusted a permitted filename extension without verifying the uploaded file's MIME type, allowing active content under an accepted extension. Low-privileged access and a victim viewing the stored upload are required; the script runs in the site's origin and can read or alter accessible data.
The record
- CVE
- CVE-2023-4652
- Published
- Aug 31, 2023
- Updated
- Oct 1, 2024
- Vendor
- InstantCMS Team
- Product
- InstantCMS 2
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 31, 2023CVE publishedPublication date reported by the CVE source.
- Oct 1, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <2.16.1-git
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
- huntr.dev stored-XSS proof of conceptproof of concept · unverified
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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