.. / CVE-2021-29441

Exploit for Nacos <1.4.1 - Authentication Bypass (CVE-2021-29441)

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.

Nuclei Template

View the template here CVE-2021-29441.yaml

Validate with Nuclei

echo "$URL" | nuclei -t ~/nuclei-templates/http/cves/2021/CVE-2021-29441.yaml
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References:

https://nvd.nist.gov/vuln/detail/CVE-2021-29441
https://github.com/bakery312/Vulhub-Reproduce
https://securitylab.github.com/advisories/GHSL-2020-325_326-nacos/
https://github.com/advisories/GHSA-36hp-jr8h-556f
https://github.com/alibaba/nacos/pull/4703
https://github.com/alibaba/nacos/issues/4701