GHSA-7cgc-fjv4-52x6 Malware in pre-build binaries of bignum

• npm bignum: >= 0.12.2, < 0.13.1 → fixed in 0.13.1

Impact bignum releases from v0.12.2 to v0.13.0 (inclusive) used node-pre-gyp to optionally download pre-built binary versions of the addon. These binaries were published on a now-expired S3 bucket which has since been claimed by a malicious third party which is now serving binaries containing malware that exfiltrates data from the user's computer. Patches v0.13.1 does not use node-pre-gyp and does not have support for downloading pre-built binaries in any form, avoiding the risk of malicious downloads.