savg-sanitizer is a PHP SVG/XML sanitizer. Prior to 1.0.0, svg-sanitizer's isHrefSafeValue() validates an SVG href after XML DTD entity expansion, but saveXML() serializes the original entity reference after removing the DTD declaration. A crafted entity such as Tab can appear to the sanitizer as a safe fragment prefix while HTML5 Named Character Reference resolution during inline HTML rendering later converts the surviving reference to whitespace, exposing a javascript: URL.
When an application embeds the sanitized SVG inline, a user who activates the link can cause script to execute in the embedding page's origin. This issue is fixed in version 1.0.0.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
Required
User action required
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 3
https://github.com/darylldoyle/svg-sanitizer/commit/23877db7e76f1e1df5c3e65ab30…
security-advisories@github.com
https://github.com/darylldoyle/svg-sanitizer/releases/tag/1.0.0
security-advisories@github.com
https://github.com/darylldoyle/svg-sanitizer/security/advisories/GHSA-9rjx-3jch…
security-advisories@github.com