CWE-1236

Improper Neutralization of Formula Elements in a CSV File
AI Translation Available

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.

Status
incomplete
Abstraction
base
Other

Common Consequences

confidentiality
Impacts
read application data execute unauthorized code or commands

Detection Methods

automated static analysis

Potential Mitigations

Phases:
implementation architecture and design
Descriptions:
• If a field starts with a formula character, prepend it with a ' (single apostrophe), which prevents Excel from executing the formula.
• 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).
• 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.