GHSA-p28h-cc7q-c4fg: css-what vulnerable to ReDoS due to use of insecure regular expression

Ubuntu Security Notice 6065-1 - It was discovered that css-what incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service.

The package css-what before 2.1.3 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the usage of insecure regular expression in the re_attr variable of index.js. The exploitation of this vulnerability could be triggered via the parse function.