CVE-2025-8838
Published: 11 August 2025
Summary
CVE-2025-8838 is a medium-severity Improper Authentication (CWE-287) vulnerability in Winterchens My-Site. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 39.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and IA-2 (Identification and Authentication (Organizational Users)).
Deeper analysis
CVE-2025-8838 is an improper authentication vulnerability (CWE-287) in the WinterChenS my-site project, affecting commits up to 1f7525f15934d9d6a278de967f6ec9f1757738d8. The issue resides in the preHandle function within the /admin/ Backend Interface component, where manipulation of the uri argument bypasses authentication checks. This flaw carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L), indicating high severity due to its network accessibility and low complexity.
The vulnerability can be exploited remotely by unauthenticated attackers with no privileges required and no user interaction needed. Successful exploitation allows limited impacts on confidentiality, integrity, and availability, potentially enabling unauthorized access to backend administrative functions through crafted URI manipulations. An exploit has been publicly disclosed, though its practical reliability remains in question.
Advisories from VulDB and GitHub issue #97 detail the report, with the project maintainer responding that testing the reported link results in an automatic redirect to the login page, suggesting the issue may not function as claimed. As my-site employs a rolling release model for continuous delivery, no specific affected or patched versions are available; practitioners should monitor the repository for updates.
Notable context includes ongoing doubt about the vulnerability's validity, as confirmed by the maintainer's reproduction attempts, with no evidence of real-world exploitation reported to date.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-24136
Vulnerability details
A vulnerability has been found in WinterChenS my-site up to 1f7525f15934d9d6a278de967f6ec9f1757738d8. This vulnerability affects the function preHandle of the file /admin/ of the component Backend Interface. The manipulation of the argument uri leads to improper authentication. The attack can be…
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initiated remotely. The exploit has been disclosed to the public and may be used. The real existence of this vulnerability is still doubted at the moment. This product is using a rolling release to provide continious delivery. Therefore, no version details for affected nor updated releases are available. The code maintainer responded to the issue that "[he] tried it, and using this link automatically redirects to the login page."
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Improper authentication bypass in public-facing /admin backend interface directly enables remote exploitation of a web application vulnerability.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces authentication decisions on the /admin/ backend before any URI-based request is honored, blocking the reported bypass.
Requires successful identification and authentication of users prior to granting access to the administrative interface that the flaw exposes.
Validates the uri argument supplied to preHandle, preventing crafted values from bypassing the authentication check.