CVE-2021-41177
Published: 25 October 2021
Summary
CVE-2021-41177 is a high-severity Improper Control of Interaction Frequency (CWE-799) vulnerability in Nextcloud Nextcloud Server. Its CVSS base score is 8.1 (High).
Operationally, ranked in the top 29.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-28279
Vulnerability details
Nextcloud is an open-source, self-hosted productivity platform. Prior to versions 20.0.13, 21.0.5, and 22.2.0, Nextcloud Server did not implement a database backend for rate-limiting purposes. Any component of Nextcloud using rate-limits (as as `AnonRateThrottle` or `UserRateThrottle`) was thus not rate…
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limited on instances not having a memory cache backend configured. In the case of a default installation, this would notably include the rate-limits on the two factor codes. It is recommended that the Nextcloud Server be upgraded to 20.0.13, 21.0.5, or 22.2.0. As a workaround, enable a memory cache backend in `config.php`.
- 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.
The control requires defining frequency, timing, and approval for security interactions, directly addressing uncontrolled interaction rates.
Allocation policies inherently restrict interaction frequency, reducing the impact of excessive requests.
Spam protection explicitly controls interaction frequency by detecting and acting on bulk unsolicited messages from external sources.