NVD / CVE Program· CNA jpcert

CVE-2021-20737: Improper authentication vulnerability in GROWI versions prior to v4.2.20 allows a remote attacker to view the unauthorized pages without acc

Noroxi assessment

Priority: Monitor (action score 26/100)

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% (FIRST EPSS); higher than 64.3% 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.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

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

Improper authentication vulnerability in GROWI versions prior to v4.2.20 allows a remote attacker to view the unauthorized pages without access privileges via unspecified vectors.

MediumCVSS 6.5 · v3.1—No exploit No fix recorded

Auth bypass

Published: Jun 21, 2021
Updated: Jun 16, 2026
EPSS: 1.0% · 64th percentile
CWE: CWE-287

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 26 / 40 · 6.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.0%

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

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Noroxi analysis

What does it mean in your environment?

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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
weseek	growi	cpe:2.3:a:weseek:growi

Affected versions

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

weseek growibefore 4.2.20

Versions reported by the vendor

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

WESEEK, Inc. GROWI
- versions prior to v4.2.20affected

Same product

weseek: all records

Other highest-scoring records for the same primary product.

CVE-2021-20736NoSQL injection vulnerability in GROWI versions prior to v4.2.20 allows a remote attacker to obtain and/or alter the information stored in t
36Monitor
CVE-2019-5968Cross-site request forgery (CSRF) vulnerability in GROWI v3.4.6 and earlier allows remote attackers to hijack the authentication of administ
35Monitor
CVE-2020-5683Directory traversal vulnerability in GROWI versions prior to v4.2.3 (v4.2 Series), GROWI versions prior to v4.1.12 (v4.1 Series), and GROWI
31Monitor

Published before and after this one in the same product

← EarlierCVE-2021-20672Mar 10, 2021 · Reflected cross-site scripting vulnerability due to insufficient verification of URL query parameters in GROWI (v4.2 Series) versions from v
24Monitor
← EarlierCVE-2021-20673Mar 10, 2021 · Stored cross-site scripting vulnerability in Admin Page of GROWI (v4.2 Series) versions from v4.2.0 to v4.2.7 allows remote authenticated at
19Monitor
Later →CVE-2021-20829Sep 21, 2021 · Cross-site scripting vulnerability due to the inadequate tag sanitization in GROWI versions v4.2.19 and earlier allows remote attackers to e
24Monitor

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

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

No commit or PR link among the references.

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.

—

Chain candidates

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

CVE-2021-20671103 days apartInvalid file validation on the upload feature in GROWI versions v4.2.2 allows a remote attacker with administrative privilege to overwrite t
29Monitor
CVE-2021-20669103 days apartPath traversal vulnerability in GROWI versions v4.2.2 and earlier allows an attacker with administrator rights to read and/or delete an arbi
18Monitor
CVE-2021-20668103 days apartPath traversal vulnerability in GROWI versions v4.2.2 and earlier allows an attacker with administrator rights to read an arbitrary path via
10Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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: none
Availability: none

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

Weakness class (CWE)

CWE-287 · Improper Authentication

CVSS vector

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

nvd-primary

Root cause

Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.

The bug in code

The whole CWE-287 class

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

Vulnerable

1app.use("/admin", requireSession, adminRouter);
2

3// Route added later skips the middleware
4app.post("/admin-api/config", updateConfig);

Fixed

1const admin = express.Router();
2admin.use(requireSession, requireRole("admin"));
3

4admin.post("/config", updateConfig);
5app.use("/admin", admin);

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

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

jvn.jp/en/jp/JVN95457785/index.html

Show all references (1 more)

weseek.co.jp/security/2021/06/14/vulnerability/growi-nosql-ingection/

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

All records