CVE-2021-29441

HIGH EXPLOITED IN THE WILD NUCLEI

Alibaba Nacos < 1.4.1 - Authentication Bypass by Spoofing

Title source: rule

Description

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.

Exploits (4)

nomisec WORKING POC
by azhao1981 · poc
https://github.com/azhao1981/CVE-2021-29441
nomisec STUB
by hh-hunter · poc
https://github.com/hh-hunter/nacos-cve-2021-29441
vulncheck_xdb WORKING POC
remote
https://github.com/bysinks/CVE-2021-29441
inthewild WORKING POC
poc
https://github.com/bysinks/cve-2021-29441

Nuclei Templates (1)

Nacos <1.4.1 - Authentication Bypass
CRITICALby dwisiswant0

Scores

CVSS v3 8.6
EPSS 0.9392
EPSS Percentile 99.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Details

VulnCheck KEV 2023-12-01
InTheWild.io 2021-04-12
CWE
CWE-290
Status published
Products (2)
alibaba/nacos < 1.4.1
com.alibaba.nacos/nacos-common 0 - 1.4.1Maven
Published Apr 27, 2021
Tracked Since Feb 18, 2026