Zod denial of service vulnerability during email validation
### Impact
API servers running `express-zod-api` having:
- version of `express-zod-api` below `10.0.0-beta1`,
- and using the following (or similar) validation schema in its implementation: `z.string().email()`,
are vulnerable to a DoS attack due to:
- Inefficient Regular Expression Complexity in `zod` versions up to `3.22.2`,
- depending on `zod`.
### Patches
The patched version of `zod` fixing the vulnerability is `3.22.3`.
However, it's highly recommended to upgrade `express-zod-api` to at least version `10.0.0`, which does not depend on `zod` strictly and directly, but requires its installation as a peer dependency instead, enabling you to install the patched `zod` version yourself.
### Workarounds
When it's not possible to upgrade your dependencies, consider the following replacement in your implementation:
```diff
- z.string().email()
+ z.string().regex(
+ /^(?!\.)(?!.*\.\.)([A-Z0-9_+-\.]*)[A-Z0-9_+-]@([A-Z0-9][A-Z0-9\-]*\.)+[A-Z]{2,}$/i
+ )
```
This regular expression is taken from the suggested patch of `zod`.
### References
- Original issue:
https://github.com/colinhacks/zod/issues/2609
- The patch:
https://github.com/colinhacks/zod/pull/2824
- Entry in database:
https://nvd.nist.gov/vuln/detail/CVE-2023-4316
- Enumeration:
https://cwe.mitre.org/data/definitions/1333.html
- Parent advisory:
https://github.com/advisories/GHSA-m95q-7qp3-xv42
- Changelog entry for `express-zod-api` version `10.0.0-beta1`:
https://github.com/RobinTail/express-zod-api/blob/master/CHANGELOG.md#v1000-beta1