CVE-2020-26251
What it is
Open Zaak is a modern, open-source data- and services-layer to enable zaakgericht werken, a Dutch approach to case management. In Open Zaak before version 1.3.3 the Cross-Origin-Resource-Sharing policy in Open Zaak is currently wide open - every client is allowed. This allows evil.com to run scripts that perform AJAX calls to known Open Zaak installations, and the browser will not block these. This was intended to only apply to development machines running on localhost/127.0.0.1. Open Zaak 1.3.3 disables CORS by default, while it can be opted-in through environment variables. The vulnerability does not actually seem exploitable because: a) The session cookie has a `Same-Site: Lax` policy which prevents it from being sent along in Cross-Origin requests. b) All pages that give access to (production) data are login-protected c) `Access-Control-Allow-Credentials` is set to `false` d) CSRF checks probably block the remote origin, since they're not explicitly added to the trusted allowlist.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 4.7 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-346
- Record status
- Modified
Affected
- Openzaak Open Zaak < 1.3.3
Attack profile CVSS 3.1 · 4.7
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2020-26251.md and follow it. Check whether this project is affected by CVE-2020-26251. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/open-zaak/open-zaak/commit/952269269f1b629fce9c94485f83ac13f31d6c46
- https://github.com/open-zaak/open-zaak/security/advisories/GHSA-chhr-gxrg-64x7
- https://github.com/open-zaak/open-zaak/commit/952269269f1b629fce9c94485f83ac13f31d6c46
- https://github.com/open-zaak/open-zaak/security/advisories/GHSA-chhr-gxrg-64x7
References
- https://github.com/open-zaak/open-zaak/blob/master/CHANGELOG.rst#133-2020-12-17
- https://github.com/open-zaak/open-zaak/commit/952269269f1b629fce9c94485f83ac13f31d6c46
- https://github.com/open-zaak/open-zaak/security/advisories/GHSA-chhr-gxrg-64x7
- https://github.com/open-zaak/open-zaak/blob/master/CHANGELOG.rst#133-2020-12-17
- https://github.com/open-zaak/open-zaak/commit/952269269f1b629fce9c94485f83ac13f31d6c46
- https://github.com/open-zaak/open-zaak/security/advisories/GHSA-chhr-gxrg-64x7