CVE-2023-37266
Published: 17 July 2023
Summary
CVE-2023-37266 is a critical-severity Improper Authentication (CWE-287) vulnerability in Icewhale Casaos. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 0.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis
CasaOS, an open-source personal cloud platform, contains an authentication bypass vulnerability (CWE-287) that allows unauthenticated attackers to forge valid JWTs. The flaw stems from insufficient validation of JWT signatures and claims, enabling access to privileged endpoints that normally require authentication. The issue affects all versions prior to the patch and carries a CVSS 3.1 score of 9.8.
An attacker with network access can craft arbitrary JWT tokens, invoke authenticated API functions, and ultimately execute arbitrary commands with root privileges on the underlying host. No user interaction or prior credentials are required, making the attack remotely exploitable against any publicly reachable CasaOS instance.
The official advisory and patch in commit 705bf1f, released as part of CasaOS 0.4.4, strengthen JWT validation to reject forged tokens. Administrators unable to upgrade are advised to restrict network exposure, for example by removing public accessibility or placing the service behind an authenticated reverse proxy.
The associated EPSS score of 0.8916 indicates substantial exploitation interest following disclosure. Public references include a detailed analysis from SonarSource that maps the JWT weaknesses to concrete attack paths.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-2095
Vulnerability details
CasaOS is an open-source Personal Cloud system. Unauthenticated attackers can craft arbitrary JWTs and access features that usually require authentication and execute arbitrary commands as `root` on CasaOS instances. This problem was addressed by improving the validation of JWTs in…
more
commit `705bf1f`. This patch is part of CasaOS 0.4.4. Users should upgrade to CasaOS 0.4.4. If they can't, they should temporarily restrict access to CasaOS to untrusted users, for instance by not exposing it publicly.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Detects unauthorized successful logons resulting from improper authentication implementations.
Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.
Security awareness training instructs users on secure authentication practices and avoiding credential compromise.
Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.
Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.
Session content review can reveal authentication bypasses or failures in session establishment.
Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.