Common Weakness Enumeration
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CWE-1236
Improper Neutralization of Formula Elements in a CSV File
The product saves user-provided information into a Comma-Separated Value (CSV) file, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as a command when the file is opened by a spreadsheet product.
Mitigation
Phase: Implementation
Description:
- When generating CSV output, ensure that formula-sensitive metacharacters are effectively escaped or removed from all data before storage in the resultant CSV. Risky characters include '=' (equal), '+' (plus), '-' (minus), and '@' (at).
Mitigation
Phase: Implementation
Description:
- If a field starts with a formula character, prepend it with a ' (single apostrophe), which prevents Excel from executing the formula.
Mitigation
Phase: Architecture and Design
Description:
- Certain implementations of spreadsheet software might disallow formulas from executing if the file is untrusted, or if the file is not authored by the current user.
No CAPEC attack patterns related to this CWE.