Cross-site scripting via malformed widget undo data
Published Aug 12, 2021 · Updated Aug 3, 2024
Cross-site scripting in CKSource CKEditor 4 4.13.0 through 4.16.1 allows remote authenticated users to execute JavaScript via malformed widget HTML. The Widget plugin undo filter uses a regular expression to strip drag-handler spans from serialized undo data; malformed nested markup can make that rewrite restore executable DOM. Exploitation requires Widget and Undo, low-privileged access to supply editor content, and user interaction to invoke undo; code runs in the editor page browser context.
Summary
What happened
Cross-site scripting in CKSource CKEditor 4 4.13.0 through 4.16.1 allows remote authenticated users to execute JavaScript via malformed widget HTML. The Widget plugin undo filter uses a regular expression to strip drag-handler spans from serialized undo data; malformed nested markup can make that rewrite restore executable DOM. Exploitation requires Widget and Undo, low-privileged access to supply editor content, and user interaction to invoke undo; code runs in the editor page browser context.
The record
- CVE
- CVE-2021-32808
- Published
- Aug 12, 2021
- Updated
- Aug 3, 2024
- Vendor
- CKSource
- Product
- CKEditor 4
- Classifications
- CWE-79, T1203
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 12, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 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=>= 4.13.0, < 4.16.2
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
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.
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Technologies
Your stack
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Your stack
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