Affected versions of sequelize are vulnerable to SQL Injection when user input is passed into findOne or into a statement such as where: "user input".

Recommendation

Update to version 3.0.0 or later.

Version 3.0.0 will introduce a number of breaking changes.
Thankfully, the project authors have provided a 2.x -> 3.x upgrade guide to ease this transition.

If upgrading is not an option, it is also possible to mitigate this by ensuring that all uses of where: "input" and findOne("input") are properly sanitized, such as by the use of a wrapper function.

References

• https://nvd.nist.gov/vuln/detail/CVE-2016-10553
• GHSA-2v7q-2xqx-f4q5
• https://www.npmjs.com/advisories/109
• https://github.com/sequelize/sequelize/blob/master/changelog.md#300