RTF Roulette: The Hidden Dangers of Storing Rich Text in VARCHAR Fields

Think RTF Is Just ASCII? Think Again!

RTF files can include binary data, and it is done using the \bin control word.

Details:

• The \binN control word is used to specify that the next N bytes in the file should be interpreted as raw binary data, not as RTF control words or ASCII text.
• This is typically used for embedding objects like images, OLE objects, or non-text attachments.

Don’t Trust VARCHAR with Binary Data

Storing RTF documents containing binary data directly in a VARCHAR database field is risky because binary sections (introduced with the \bin keyword) can include non-printable or control characters that may corrupt text-based storage, cause encoding issues, or break applications expecting valid character data. This can lead to data loss, retrieval errors, or security vulnerabilities if binary content is interpreted incorrectly. A safer approach is to store the entire RTF document as a BLOB (Binary Large Object), which preserves the raw data accurately and supports both textual and binary components without risking corruption.

From the RTF 1.9.1 specification:

“RTF files are usually 7-bit ASCII plain text, consisting of control words, control symbols, and groups. RTF files are easily transmitted between most PC based operating systems because of their 7-bit ASCII characters. However, converters that communicate with Microsoft Word for Windows or Microsoft Word for the Macintosh should expect data transfer as 8-bit characters and binary data (see \binN) can contain any 8-bit values.” (…)

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[MSFT-RTF] Microsoft Corporation, “Rich Text Format (RTF) Specification”, version 1.9.1, March 2008, https://go.microsoft.com/fwlink/?LinkId=120924