A security issue was identified in the range filter module of nginx < 1.13.3. A specially crafted request might result in an integer overflow and incorrect processing of ranges, potentially resulting in sensitive information leak.
When using nginx with standard modules this allows an attacker to obtain a cache file header if a response was returned from cache. In some configurations a cache file header may contain IP address of the backend server or other sensitive information. Besides, with 3rd party modules it is potentially possible that the issue may lead to a denial of service or a disclosure of a worker process memory. No such modules are currently known though.