Swift Prometheus is a Swift client for the Prometheus monitoring system, supporting counters, gauges and histograms. In code which applies _un-sanitized string values into metric names or labels_, an attacker could make use of this and send a `?lang` query parameter containing newlines, `}` or similar characters which can lead to the attacker taking over the exported format -- including creating unbounded numbers of stored metrics, inflating server memory usage, or causing "bogus" metrics. This vulnerability is fixed in2.0.0-alpha.2.
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.