Auth bypass in Duendesoftware Identityserver
CVE-2024-49755
Duende IdentityServer is an OpenID Connect and OAuth 2.x framework for ASP.NET Core. IdentityServer's local API authentication handler performs insufficient validation of the cnf claim in DPoP access tokens. This allows an attacker to use leaked DPoP access tokens at local api endpoints even without possessing the private key for signing proof tokens. Note that this only impacts custom endpoints within an IdentityServer implementation that have explicitly used the LocalApiAuthenticationHandler for authentication. This vulnerability is patched in IdentityServer 7.0.8. Version 6.3 and below are unaffected, as they do not support DPoP in Local APIs.
Vulnerability class: Broken Authentication
EPSS: 0.003 (24.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N.
Affected products
- Duendesoftware Identityserver — versions >= 7.0.0, < 7.0.8
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2024-49755?
- CVE-2024-49755 is a low-severity vulnerability in Duendesoftware Identityserver, classified under Improper Authentication. CVSS score: 3.1/10. Published 2024-10-28.
- How severe is CVE-2024-49755?
- Low severity. CVSS v3 base score is 3.1 out of 10.