TI-2021-10154 Aliases CVE-2021-29441 GHSA-36hp-jr8h-556f

Authentication bypass in Alibaba nacos

HIGH 83CWE-290Published 2021-04-27 · Updated 2024-08-03

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-290.

Summary

Nacos is a platform designed for dynamic service discovery and configuration and service management. In Nacos before version 1.4.1, when configured to use authentication (-Dnacos.core.auth.enabled=true) Nacos uses the AuthFilter servlet filter to enforce authentication. This filter has a backdoor that enables Nacos servers to bypass this filter and therefore skip authentication checks. This mechanism relies on the user-agent HTTP header so it can be easily spoofed. This issue may allow any user to carry out any administrative tasks on the Nacos server.

Why it matters now

EPSS 0.83236 99th percentileScored 2026-11-07

Public exploit Yes 2 exploit referencesTagged by NVD

Fix Fixed nacos (alibaba): 1.4.1com.alibaba.nacos:nacos-common (Maven): 1.4.1

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Alibaba	nacos	before 1.4.1	1.4.1	Patch available	CNA
—	com.alibaba.nacos:nacos-common (Maven)	before 1.4.1	1.4.1	Patch available	GHSA-36hp-jr8h-556f

nacos VendorAlibaba Affected before 1.4.1 Fixed in 1.4.1 Patch available CNA
com.alibaba.nacos:nacos-common (Maven) Vendor— Affected before 1.4.1 Fixed in 1.4.1 Patch available GHSA-36hp-jr8h-556f

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:alibaba:nacos::::::::	before 1.4.1	Vulnerable	Alibaba

cpe:2.3:a:alibaba:nacos:*:*:*:*:*:*:*:* Versions before 1.4.1 Vulnerable ·Alibaba

Remediation

Fix · CNA nacos (alibaba) Fixed in 1.4.1
Fix · GHSA-36hp-jr8h-556f com.alibaba.nacos:nacos-common (Maven) Fixed in 1.4.1 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2021-29441
2026-10-03 Alias added: GHSA-36hp-jr8h-556f

References

Exploit 2

Patch 1

https://github.com/alibaba/nacos/pull/4703

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2021-29441

TI-2021-10155 Authentication bypass in Alibaba nacos CVSS 3.1HIGH 8.6
TI-2021-19162 An Access Control vulnerability exists in Nacos 2.0.3 in the access prompt page; enter… CVSS 3.1HIGH 8.8
TI-2021-20198 A Cross Site Scripting (XSS) vulnerability exists in Nacos 2.0.3 in auth/users via the… CVSS 3.1MEDIUM 6.1
TI-2020-13672 Nacos 1.1.4 is affected by: Incorrect Access Control. CVSS 3.1MEDIUM 5.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences