Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2021-29441— Authentication bypass

Quick assessment

Affected
alibaba nacos
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

nacos是中国阿里巴巴（Alibaba）的一个动态服务发现、配置和服务管理平台。该软件支持基于 DNS 和基于 RPC 的服务发现，可提供提供实时健康检查，阻止服务向不健康的主机或服务实例发送请求等功能。 Nacos 存在安全漏洞，该漏洞源于允许Nacos服务器绕过过滤器，从而跳过身份验证检查。这种机制依赖于用户代理HTTP头，因此很容易被欺骗。

CVSS 8.6 · High EPSS 83.48% · P100

Public Exploits 1

Nuclei · 1 CVE-2021-29441.yaml [template]
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2021-29441

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Authentication bypass
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
使用欺骗进行的认证绕过
Source: CVE Program / CVE List V5
Vulnerability Title
Nacos 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
nacos是中国阿里巴巴（Alibaba）的一个动态服务发现、配置和服务管理平台。该软件支持基于 DNS 和基于 RPC 的服务发现，可提供提供实时健康检查，阻止服务向不健康的主机或服务实例发送请求等功能。 Nacos 存在安全漏洞，该漏洞源于允许Nacos服务器绕过过滤器，从而跳过身份验证检查。这种机制依赖于用户代理HTTP头，因此很容易被欺骗。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Shenlong Deep Dive — AI Deep Analysis

10-question deep dive: root cause, exploitation, mitigation, urgency. Read summary free, full version requires login.

Read summary Full analysis (login)

Affected Products

Vendor Product Affected Versions CPE Subscribe
alibaba nacos < 1.4.1 -

II. Public POCs for CVE-2021-29441

# POC Description Source Link Shenlong Link
1 None https://github.com/hh-hunter/nacos-cve-2021-29441 POC Details
2 None https://github.com/bysinks/CVE-2021-29441 POC Details
3 None https://github.com/azhao1981/CVE-2021-29441 POC Details
4 This template only works on Nuclei engine prior to version 2.3.3 and version >= 2.3.5. 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. https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-29441.yaml POC Details
5 None https://github.com/Threekiii/Awesome-POC/blob/master/%E4%BA%91%E5%AE%89%E5%85%A8%E6%BC%8F%E6%B4%9E/Nacos%20%E8%AE%A4%E8%AF%81%E7%BB%95%E8%BF%87%E6%BC%8F%E6%B4%9E%20CVE-2021-29441.md POC Details
6 https://github.com/vulhub/vulhub/blob/master/nacos/CVE-2021-29441/README.md POC Details
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2021-29441

请登录查看更多情报信息。

Other References for CVE-2021-29441 (2)

IV. Related Vulnerabilities

Same product: nacos
Same vendor: alibaba
Same weakness: CWE-290

V. Comments for CVE-2021-29441

No comments yet

Leave a comment