CVE-2021-29441 PoC — Authentication bypass

Source

https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-29441.yaml

Associated Vulnerability

Title: Authentication bypass (CVE-2021-29441)
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.

Description

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.

File Snapshot

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