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CVE-2021-29441

CriticalCVSS 9.8 / 10
Published Apr 27, 2021·Last modified Apr 10, 2026
Affected Components(0)

No affected components available

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.

Risk Scores
Base Score
9.8

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.

Threat Intelligence
9.3

Active exploitation in the wild has been confirmed. Immediate patching or mitigation is required.

EPSS
68.92%

The exploit probability is very high. The vulnerability is very likely to be exploited in the next 30 days.

Exploit
Proof of Concept

A proof of concept is available for this vulnerability (3 exploits found).

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