title: Vega has cross-site scripting vulnerability in `lassoAppend` function
description: Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs.`lassoAppend' function accepts 3 arguments and internally invokes `push` function on the 1st argument specifying array consisting of 2nd and 3rd arguments as `push` call argument. The type of the 1st argument is supposed to be an array, but it's not enforced. This makes it possible to specify any object with a `push` function as the 1st argument, `push` function can be set to any function that can be access via `event.view` (no all such functions can be exploited due to invalid context or signature, but some can, e.g. `console.log`). The issue is that`lassoAppend` doesn't enforce proper types of its arguments. This issue opens various XSS vectors, but exact impact and severity depends on the environment (e.g. Core JS `setImmediate` polyfill basically allows `eval`-like functionality). This issue was patched in 5.23.0.
problem types: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
affected:
{
vendor: vega
product: vega
versions:
version: < 5.23.0, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: LOW
integrityImpact: LOW
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
version: 3.1
]