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CVE-2021-41177

27
FAUCET Score

CVE-2021-41177 is a high-severity vulnerability affecting Nextcloud Server versions prior to 20.0.13, 21.0.5, and 22.2.0. The vulnerability stems from the lack of a database backend for rate-limiting, which, in default installations without a configured memory cache, allowed attackers to bypass rate limits on features like two-factor authentication codes. With a CVSS score of 8.1, this flaw presents a low-complexity network attack vector that could lead to high impact on confidentiality and availability. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
< 20.0.13CPE matchmatch criteria
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*
>= 21.0.0, < 21.0.5CPE matchmatch criteria
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*
>= 22.0.0, < 22.2.0CPE matchmatch criteria
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.1HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.2
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.50%
Probability of exploitation in next 30 days
EPSS Percentile
71.6%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0150 is in the 69th percentile among its peer group of 17,844 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

github_advisorypatch availablevia nvd_reference
View patch

References

github.com / nextcloud/security-advisories/security/advisories/GHSA-fj39-4qx4-m3f2
Third Party Advisory
github.com / nextcloud/server/pull/28728
PatchThird Party Advisory
hackerone.com / reports/1265709
Permissions RequiredThird Party Advisory
security.gentoo.org / glsa/202208-17
Third Party Advisory