NVD / CVE Program· CNA GitHub_M

CVE-2021-32800: Bypass of Two Factor Authentication in Nextcloud server

HighCVSS 8.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 33/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.7% (FIRST EPSS); higher than 78.7% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: nextcloud (openSUSE:Leap 15.2) 20.0.12-lp152.3.12.1; nextcloud (openSUSE:Leap 15.3) 20.0.12-bp153.2.6.1; nextcloud (SUSE:Package Hub 12) 20.0.12-31.1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to nextcloud (openSUSE:Leap 15.2) 20.0.12-lp152.3.12.1; nextcloud (openSUSE:Leap 15.3) 20.0.12-bp153.2.6.1; nextcloud (SUSE:Package Hub 12) 20.0.12-31.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Nextcloud server is an open source, self hosted personal cloud. In affected versions an attacker is able to bypass Two Factor Authentication in Nextcloud. Thus knowledge of a password, or access to a WebAuthN trusted device of a user was sufficient to gain access to an account. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. There are no workaround for this vulnerability.

Auth bypass

Published: Sep 7, 2021
Updated: Jun 16, 2026
EPSS: 1.7% · 78th percentile
CWE: CWE-306

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 32 / 40 · 8.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 1 / 30 · 1.7%

CNA vs NVD score

NVD: 8.1
CNA · GitHub_M: 8.1; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
nextcloud	nextcloud server	cpe:2.3:a:nextcloud:nextcloud_server

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

nextcloud security-advisories
- < 20.0.12, >= 21.0.0, < 21.0.4, >= 22.0.0, < 22.1.0affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

nextcloud nextcloud serverbefore 20.0.12
nextcloud nextcloud server21.0.0 and later · before 21.0.4
nextcloud nextcloud server22.0.0 and later · before 22.1.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
openSUSE:Leap 15.2	nextcloud	before 20.0.12-lp152.3.12.1	20.0.12-lp152.3.12.1
openSUSE:Leap 15.3	nextcloud	before 20.0.12-bp153.2.6.1	20.0.12-bp153.2.6.1
SUSE:Package Hub 12	nextcloud	before 20.0.12-31.1	20.0.12-31.1
SUSE:Package Hub 15 SP1	nextcloud	before 20.0.12-bp151.3.18.1	20.0.12-bp151.3.18.1
SUSE:Package Hub 15 SP2	nextcloud	before 20.0.12-bp152.2.12.1	20.0.12-bp152.2.12.1
SUSE:Package Hub 15 SP3	nextcloud	before 20.0.12-bp153.2.6.1	20.0.12-bp153.2.6.1

Same product

nextcloud: all records

Other highest-scoring records for the same primary product.

CVE-2023-26482Scope of workflow operations is not validated in nextcloud server
40Plan
CVE-2021-32802Preview generation used third-party library not suited for user-generated content in Nextcloud server
40Plan
CVE-2021-32726Webauthn tokens not removed after user has been deleted
40Plan

Published before and after this one in the same product

← EarlierCVE-2021-32741Jul 12, 2021 · Lack of ratelimit on public share link mount endpoint
21Monitor
← EarlierCVE-2021-32766Sep 7, 2021 · Nextcloud Text app can disclose existence of folders in "File Drop" link share
21Monitor
Later →CVE-2021-32801Sep 7, 2021 · Exceptions may have logged Encryption-at-Rest key content in Nextcloud server
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
opensuse:nextcloud	20.0.12-bp153.2.6.1 · openSUSE:Leap 15.3	Package registry (OSV)
opensuse:nextcloud	20.0.12-lp152.3.12.1 · openSUSE:Leap 15.2	Package registry (OSV)
suse:nextcloud	20.0.12-bp151.3.18.1 · SUSE:Package Hub 15 SP1	Package registry (OSV)
suse:nextcloud	20.0.12-bp153.2.6.1 · SUSE:Package Hub 15 SP3	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

nextcloud/serverPR 28078

Bug bounty scope

NextcloudHackerOne · paid

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0717 · Sep 8, 2021(Nextcloud Zafiyeti)

All national notices →

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: None

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

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

nvd-primary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/nextcloud/security-advisories/security/advisories/GHSA-gv5w-8q25-785v

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records