@dicebear/converter vulnerable to ncontrolled memory allocation via crafted SVG dimensions

DiceBear is an avatar library for designers and developers. Prior to version 9.4.0, the ensureSize() function in @dicebear/converter read the width and height attributes from the input SVG to determine the output canvas size for rasterization (PNG, JPEG, WebP, AVIF). An attacker who can supply a crafted SVG with extremely large dimensions (e.g. width="999999999") could force the server to allocate excessive memory, leading to denial of service. This primarily affects server-side applications that pass untrusted or user-supplied SVGs to the converter's toPng(), toJpeg(), toWebp(), or toAvif() functions. Applications that only convert self-generated DiceBear avatars are not practically exploitable, but are still recommended to upgrade. This is fixed in version 9.4.0. The ensureSize() function no longer reads SVG attributes to determine output size. Instead, a new size option (default: 512, max: 2048) controls the output dimensions. Invalid values (NaN, negative, zero, Infinity) fall back to the default. If upgrading is not immediately possible, validate and sanitize the width and height attributes of any untrusted SVG input before passing it to the converter.