Vulnerability · Published Oct 25, 2021 · Assigned by GitHub_M

CVE-2021-41177Rate-limits not working on instances without configured memory cache backend

High 8.1

In plain English

A high-severity security flaw in security-advisories from nextcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.6% (higher than 75% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)1.6%top 24.8% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

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 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`.

Affected products (as reported)

Vendor	Product	Versions
nextcloud	security-advisories	< 20.0.13>= 21.0.0, < 21.0.5< 22.2.0

Weakness: CWE-799 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-fj39-4qx4-m3f2 x_refsource_CONFIRM
https://github.com/nextcloud/server/pull/28728 x_refsource_MISC
https://hackerone.com/reports/1265709 x_refsource_MISC
GLSA-202208-17 vendor-advisory, x_refsource_GENTOO