@dicebear/converter ensureSize() Vulnerable to SVG Dimension Capping Bypass via XML Comment Injection
DiceBear is an avatar library for designers and developers. Prior to version 9.4.2, the `ensureSize()` function in `@dicebear/converter` used a regex-based approach to rewrite SVG `width`/`height` attributes, capping them at 2048px to prevent denial of service. This size capping could be bypassed by crafting SVG input that causes the regex to match a non-functional occurrence of `<svg` before the actual SVG root element. When the SVG is subsequently rendered via `@resvg/resvg-js` on the Node.js code path, it renders at the attacker-specified dimensions, potentially causing out-of-memory crashes. In version 9.4.2, the regex-based approach has been replaced with XML-aware processing using `fast-xml-parser` to correctly identify and modify the SVG root element's attributes. Additionally, a `fitTo` constraint has been added to the `renderAsync` call as defense-in-depth, ensuring the rendered output is always bounded regardless of SVG content.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-185 | CWE-185: Incorrect Regular Expression |
Type: CWE
Description: CWE-185: Incorrect Regular Expression
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 3.1 | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Version: 3.1
Base score: 7.5
Base severity: HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H