next-auth: Incorrect Authorization
CVE-2022-35924 is a critical-severity incorrect authorization vulnerability in next-auth from Nextauthjs, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected next-auth versions: >= 4.0.0, < 4.10.3; < 3.29.10. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.47% chance of exploitation within 30 days, higher than 74% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of next-auth you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Nextauthjs | next-auth | >= 4.0.0, < 4.10.3; < 3.29.10 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.1 | Critical | CNA (github.com) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official description
NextAuth.js is a complete open source authentication solution for Next.js applications. `next-auth` users who are using the `EmailProvider` either in versions before `4.10.3` or `3.29.10` are affected. If an attacker could forge a request that sent a comma-separated list of emails (eg.: `[email protected],[email protected]`) to the sign-in endpoint, NextAuth.js would send emails to both the attacker and the victim's e-mail addresses. The attacker could then login as a newly created user with the email being `[email protected],[email protected]`. This means that basic authorization like `email.endsWith("@victim.com")` in the `signIn` callback would fail to communicate a threat to the developer and would let the attacker bypass authorization, even with an `@attacker.com` address. This vulnerability has been patched in `v4.10.3` and `v3.29.10` by normalizing the email value that is sent to the sign-in endpoint before accessing it anywhere else. We also added a `normalizeIdentifier` callback on the `EmailProvider` configuration, where you can further tweak your requirements for what your system considers a valid e-mail address. (E.g.: strict RFC2821 compliance). Users are advised to upgrade. There are no known workarounds for this vulnerability. If for some reason you cannot upgrade, you can normalize the incoming request using Advanced Initialization.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Authorization
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
How developers prevent this class of flaw
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/nextauthjs/next-auth/security/advisories/GHSA-xv97-c62v-4587Mitigation, Third Party Advisory
- next-auth.js.org/configuration/callbacks#sign-in-callback
- next-auth.js.org/configuration/initialization#advanced-initialization
- next-auth.js.org/providers/email
- next-auth.js.org/providers/email#normalizing-the-e-mail-address
Patches and release notes
- github.com/nextauthjs/next-auth/commit/afb1fcdae3cc30445038ef588e491d139b916003Third Party Advisory
Third-party and government advisories
- en.wikipedia.org/wiki/Email_address#Local-partThird Party Advisory
- nodemailer.com/message/addressesThird Party Advisory
Other vulnerabilities in next-auth
- 9.1 Critical severity
- 9.1 Critical severity
- 7.5 High severity
- 8.8 High severity
- 8.1 High severity
- 7.5 High severity
Recent Incorrect Authorization vulnerabilities
- 9.6 Critical severity
- 9.1 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 7.2 High severity
- 9.8 Critical severity
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