`CVE-2021-37580` Apache ShenYu

Affected software	Apache ShenYu
Severity	9.8 Critical CVSS 3.1 2 scores
Fixed in	`2.4.1`
Weakness	Improper authentication (CWE-287)
Published	16 Nov 2021
Updated	4 Nov 2026

Description

A flaw was found in Apache ShenYu Admin. The incorrect use of JWT in ShenyuAdminBootstrap allows an attacker to bypass authentication. This issue affected Apache ShenYu 2.3.0 and 2.4.0

Exploitation status

Exploited

Real-world exploitation reported by VulnCheck KEV. CISA has not confirmed it.

CISA KEV not listed
VulnCheck KEV listed Exploitation reported in the wild. Honeypot sightings · 5 exploits · earliest 2023-12-05.
CISA Vulnrichment no assessment published
Indexed PoC 8 indexed Published artifacts you can open, in GitHub PoC, Nuclei; first seen 2021-11-17.
EPSS 41% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99% of all scored CVEs.

VulnCheck KEV

Exploitation evidence from VulnCheck Known Exploited Vulnerabilities (VulnCheck KEV), used under VulnCheck's community terms. View CVE-2021-37580 in VulnCheck (free account).

Evidence	Source	Detail	Date
Honeypot sighting	Shadowserver honeypots	Exploitation attempts seen on 604 days	2023-12-05 to 2026-11-10
Exploit reference	VulnCheck XDB 1295b90bce32	Exploit type: info-leak	2021-11-17
Exploit reference	VulnCheck XDB 976244dc6fcb	Exploit type: initial-access	2021-11-17
Exploit reference	VulnCheck XDB 5453a6921c7a	Exploit type: initial-access	2021-11-19
Exploit reference	VulnCheck XDB bbab52ef6084	Exploit type: initial-access	2021-11-19
Exploit reference	VulnCheck XDB 7cbe2d8649ce	Exploit type: initial-access	2023-10-10

Evidence

Source

Detail

Date

Honeypot sighting

Shadowserver honeypots

Exploitation attempts seen on 604 days

2023-12-05 to 2026-11-10

Exploit reference

VulnCheck XDB 1295b90bce32

Exploit type: info-leak

2021-11-17

Exploit reference

VulnCheck XDB 976244dc6fcb

Exploit type: initial-access

2021-11-17

Exploit reference

VulnCheck XDB 5453a6921c7a

Exploit type: initial-access

2021-11-19

Exploit reference

VulnCheck XDB bbab52ef6084

Exploit type: initial-access

2021-11-19

Exploit reference

VulnCheck XDB 7cbe2d8649ce

Exploit type: initial-access

2023-10-10

4 of these are GitHub repositories with fewer than 5 stars. They are listed for reference and don't count toward the exploitation status above.

Index	Artifact	Stars	First seen
GitHub PoC	CVE-2021-37580的poc	38	2021-11-17
GitHub PoC	CVE-2021-37580	7	2021-11-19
GitHub PoC	ZororoZ/CVE-2021-37580	5	2021-11-19
GitHub PoC	rabbitsafe/CVE-2021-37580	4	2021-11-17
GitHub PoC	Apache ShenYu Admin JWT认证绕过漏洞(CVE-2021-37580)	1	2023-10-10
GitHub PoC	Apache ShenYu 管理员认证绕过		2021-11-19
GitHub PoC	A vulnerability scanner that detects CVE-2021-37580 vulnerabilities.		2021-11-19
Nuclei	Apache ShenYu Admin JWT - Authentication Bypass

Waratek protection

Protected by Waratek

Waratek has a rule that blocks attacks on this vulnerability.

Protection full
Action available patch rule
Review human ARMR file
Record active

Decided by	An ARMR patch file on disk for this CVE
Finding	CVE has an ARMR patch rule that provides mitigation

Decided by

An ARMR patch file on disk for this CVE

Finding

CVE has an ARMR patch rule that provides mitigation

ARMR rule files

1 file

The rule files Waratek ships for this CVE. Some CVEs need more than one, for example one per affected library or one per ARMR version.

CVE-2021-37580.armr patch rule, ARMR 2.6 added 2026-11-03 updated 2026-11-04

How to mitigate CVE-2021-37580

Upgrade Apache ShenYu to 2.4.1 or later. Until you can, Waratek RASP blocks exploitation with a rule written for this CVE. It runs inside the Java application, with no code changes.

Waratek RASP Runtime protection for Java applications

CVSS

9.8 CRITICAL v3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 2 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H NVD Primary published

CVSS 2.0 7.5 none AV:N/AC:L/Au:N/C:P/I:P/A:P NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	9.8	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`	NVD	Primary	published
CVSS 2.0	7.5	none	`AV:N/AC:L/Au:N/C:P/I:P/A:P`	NVD	Primary

Affected software and releases

Maven packages

Affected and fixed versions, from OSV.dev

Package Introduced Fixed Last affected

org.apache.shenyu:shenyu-admin 2.3.0 2.4.1 unbounded

Package	Introduced	Fixed	Last affected
`org.apache.shenyu:shenyu-admin`	2.3.0	`2.4.1`	unbounded

Products and versions

2 products, 3 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	apache	shenyu	generic	2.3.0 · 2.4.0
osv	org.apache.shenyu	shenyu-admin	generic	≥ 2.3.0 and ＜ 2.4.1

Source

Vendor

Product

Scheme

Affected versions

nvd

apache

shenyu

generic

2.3.0 · 2.4.0

osv

org.apache.shenyu

shenyu-admin

generic

≥ 2.3.0 and ＜ 2.4.1

References

URL	Tags
https://github.com/apache/shenyu/commit/f78adb26926ba53b4ec5c21f2cf7e931461d601d	WEB
https://github.com/apache/shenyu	PACKAGE
https://github.com/apache/shenyu/releases/tag/v2.4.1	WEB
https://lists.apache.org/thread/o15j25qwtpcw62k48xw1tnv48skh3zgb	WEB
http://www.openwall.com/lists/oss-security/2021/11/16/1	WEB

URL

Timeline

Published	2021-11-16	By the CVE Program.
VulnCheck KEV: earliest evidence	2023-12-05	Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.
NVD record modified	2026-06-17	NVD's own last-modified date for this record.
ARMR remediation created	2026-11-03	Earliest commit adding this CVE's ARMR patch or security rule.
ARMR remediation last updated	2026-11-04	Most recent commit touching this CVE's ARMR patch or security rule.
Last VRT activity	2026-11-04	Most recent commit touching this CVE's classification, patch or rule file.
VulnCheck KEV: latest evidence	2026-11-10	Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.

Published

2021-11-16

By the CVE Program.

VulnCheck KEV: earliest evidence

2023-12-05

Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.

NVD record modified

2026-06-17

NVD's own last-modified date for this record.

ARMR remediation created

2026-11-03

Earliest commit adding this CVE's ARMR patch or security rule.

ARMR remediation last updated

2026-11-04

Most recent commit touching this CVE's ARMR patch or security rule.

Last VRT activity

2026-11-04

Most recent commit touching this CVE's classification, patch or rule file.

VulnCheck KEV: latest evidence

2026-11-10

Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.

How VRT decided (2 of 24 rules ran)

2 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file decided it matched Protected by Waratek ARMR patch file exists for this CVE

3 armr-secure-rule-file not reached An ARMR security-rule template on disk for this CVE

4 manual-classification not reached A researcher's recorded decision for this specific CVE

5 manual classification not reached Manual classification of this CVE in the legacy dataset

6 non-java-upstream not reached A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component not reached The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side not reached Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven not reached An OSV.dev record of this CVE affecting a package published to Maven Central. When every such package is one business applications do not use (Minecraft mods and launchers, Fastjson) and no tracked product is named by CPE, it settles the CVE as Outside Waratek scope instead

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint not reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven not reached The affected package being open source on Maven, so the fix can be read

19 poc-derivable not reached An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit not reached Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match not reached A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc not reached Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold not reached Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published not reached Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

NVD ↗ · CVE.org ↗