Node.js had a bug in versions 8.X and 9.X which caused buffers to not be initialized when the encoding for the fill value did not match the encoding specified. For example, 'Buffer.alloc(0x100, "This is not correctly encoded", "hex");' The buffer implementation was updated such that the buffer will be initialized to all zeros in these cases.

References

• https://nvd.nist.gov/vuln/detail/CVE-2017-15897
• https://nodejs.org/en/blog/vulnerability/december-2017-security-releases/