Collected research

SQL Smuggling

Avi Douglen · comsecglobal.com

Defines SQL Smuggling: injection that survives validation because the database reinterprets input after the check. The new vector is Unicode homoglyph best-fit folding — U+02BC (%CA%BC) passes a quote filter or WAF, then SQL Server 2005 folds it to a real apostrophe inside a varchar parameter, breaking out of a dynamic-SQL stored procedure. Also covers MySQL backslash escaping.

Record

Researcher

Avi Douglen

Published by

comsecglobal.com

Format

Whitepaper

Topic

Injection

In the archive

• Collected in the 2008 research round

Tags

• sqli
• filter-bypass
• waf-bypass
• unicode
• charset
• mssql
• mysql
• database
• owasp-a02-2021
• owasp-a03-2021
• owasp-a05-2021

This page is the archive's own catalogue record. The research is the work of Avi Douglen, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 6 August 2026.