Nextcloud Server auth bypass via trusted proxy before v26.0.9/27.1.4
CVE-2023-49792 Published on December 22, 2023
Bruteforce protection can be bypassed with misconfigured proxy
Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. In Nextcloud Server prior to versions 26.0.9 and 27.1.4; as well as Nextcloud Enterprise Server prior to versions 23.0.12.13, 24.0.12.9, 25.0.13.4, 26.0.9, and 27.1.4; when a (reverse) proxy is configured as trusted proxy the server could be tricked into reading a wrong remote address for an attacker, allowing them executing authentication attempts than intended. Nextcloud Server versions 26.0.9 and 27.1.4 and Nextcloud Enterprise Server versions 23.0.12.13, 24.0.12.9, 25.0.13.4, 26.0.9, and 27.1.4 contain a patch for this issue. No known workarounds are available.
Vulnerability Analysis
CVE-2023-49792 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Weakness Type
Improper Restriction of Excessive Authentication Attempts
The software does not implement sufficient measures to prevent multiple failed authentication attempts within in a short time frame, making it more susceptible to brute force attacks.
Products Associated with CVE-2023-49792
Want to know whenever a new CVE is published for Nextcloud Server? stack.watch will email you.
Affected Versions
nextcloud security-advisories:- Version >= 23.0.0, < 23.0.12.13 is affected.
- Version >= 24.0.0, < 24.0.12.9 is affected.
- Version >= 25.0.0, < 25.0.13.4 is affected.
- Version >= 26.0.0, < 26.0.9 is affected.
- Version >= 27.0.0, < 27.1.4 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.