Stored XSS via unsanitized SVG uploads
Published Jan 4, 2023 · Updated Apr 10, 2025
Stored cross-site scripting in phpwcms 1.9.0 through 1.9.26 allows remote authenticated users to execute script through uploaded SVG files. The SVGMetadataExtractor path reads uploaded SVG content and stores it without removing executable elements or attributes. A logged-in uploader must submit the SVG and a user must view the stored file, enabling script execution in that viewer’s browser context.
Summary
What happened
Stored cross-site scripting in phpwcms 1.9.0 through 1.9.26 allows remote authenticated users to execute script through uploaded SVG files. The SVGMetadataExtractor path reads uploaded SVG content and stores it without removing executable elements or attributes. A logged-in uploader must submit the SVG and a user must view the stored file, enabling script execution in that viewer’s browser context.
The record
- CVE
- CVE-2021-4302
- Published
- Jan 4, 2023
- Updated
- Apr 10, 2025
- Vendor
- phpwcms
- Product
- phpwcms
- Classifications
- CWE-79, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 4, 2023CVE publishedPublication date reported by the CVE source.
- Apr 10, 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=1.9.0
- Affected versionversion=1.9.1
- Affected versionversion=1.9.10
- Affected versionversion=1.9.11
- Affected versionversion=1.9.12
- Affected versionversion=1.9.13
- Affected versionversion=1.9.14
- Affected versionversion=1.9.15
- Affected versionversion=1.9.16
- Affected versionversion=1.9.17
- Affected versionversion=1.9.18
- Affected versionversion=1.9.19
- Affected versionversion=1.9.2
- Affected versionversion=1.9.20
- Affected versionversion=1.9.21
- Affected versionversion=1.9.22
- Affected versionversion=1.9.23
- Affected versionversion=1.9.24
- Affected versionversion=1.9.25
- Affected versionversion=1.9.26
- Affected versionversion=1.9.3
- Affected versionversion=1.9.4
- Affected versionversion=1.9.5
- Affected versionversion=1.9.6
- Affected versionversion=1.9.7
- Affected versionversion=1.9.8
- Affected versionversion=1.9.9
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
No public exploit references are available in this record.
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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