NVD / CVE Program· CNA GitHub_M

CVE-2021-29442: Authentication bypass

Noroxi assessment

Priority: Plan (action score 49/100)

A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 64.2% (FIRST EPSS); higher than 99.2% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: com.alibaba.nacos:nacos-common (Maven) 1.4.1.

Add it to your regular patch cycle. Upgrade to com.alibaba.nacos:nacos-common (Maven) 1.4.1 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

Nacos is a platform designed for dynamic service discovery and configuration and service management. In Nacos before version 1.4.1, the ConfigOpsController lets the user perform management operations like querying the database or even wiping it out. While the /data/remove endpoint is properly protected with the @Secured annotation, the /derby endpoint is not protected and can be openly accessed by unauthenticated users. These endpoints are only valid when using embedded storage (derby DB) so this issue should not affect those installations using external storage (e.g. mysql)

HighCVSS 7.5 · v3.1—Proof of concept Fix available

Published: Apr 27, 2021
Updated: Jun 16, 2026
EPSS: 64.2% · 99th percentile
CWE: CWE-306

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 19 / 30 · 64.2%

CNA vs NVD score

NVD: 7.5
CNA · GitHub_M: 8.6; 1.1 point gap

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

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
Proof of concept exists, no weaponized module
A fix has been released

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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
alibaba	nacos	cpe:2.3:a:alibaba:nacos

Affected versions

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

alibaba nacosbefore 1.4.1

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.

alibaba nacos
- < 1.4.1affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Maven	com.alibaba.nacos:nacos-common	before 1.4.1	1.4.1

Same product

alibaba: all records

Other highest-scoring records for the same primary product.

CVE-2021-29441Authentication bypass
64This week
CVE-2021-43116An Access Control vulnerability exists in Nacos 2.0.3 in the access prompt page; enter username and password, click on login to capture pack
37Monitor
CVE-2021-44667A Cross Site Scripting (XSS) vulnerability exists in Nacos 2.0.3 in auth/users via the (1) pageSize and (2) pageNo parameters.
24Monitor

Published before and after this one in the same product

← EarlierCVE-2020-19676Sep 30, 2020 · Nacos 1.1.4 is affected by: Incorrect Access Control.
21Monitor

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
Maven:com.alibaba.nacos:nacos-common	1.4.1	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Nuclei detection template ×1
Proof-of-concept repository on GitHub ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Nuclei detection template	Nuclei template CVE-2021-29442	—
Proof-of-concept repository on GitHub	stars:3	2024-07-31
Proof-of-concept repository on GitHub	stars:0	2024-11-25

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.

PublishedApr 27, 2021
First PoCJul 31, 2024+1190 d
TodayNov 10, 2026+2023 d

EPSS, last 120 days-2% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

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

alibaba/nacosPR 4517

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

Alibaba VDPHackerOne · disclosure only (VDP)

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

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: none
Availability: none

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

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

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

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

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References

github.com/alibaba/nacos/pull/4517

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

All records