Scalable Vector Grief
Summary
A cybersecurity researcher tested eight popular SVG sanitizers and found that six of them could be bypassed. The research demonstrates how a response header can be used to execute JavaScript in Firefox, even when the response body contains harmless XML.
IFF Assessment
FOE
The bypass of SVG sanitizers indicates a new method for attackers to potentially execute malicious JavaScript, posing a threat to web applications and their users.
Defender Context
This finding highlights a critical vulnerability in how web applications handle SVG uploads and sanitization. Defenders should be aware of this bypass technique and ensure their SVG sanitizers are robust and up-to-date, or implement additional checks to prevent XSS attacks.