CVE-2021-29441 Authentication bypass

2021-04-2720:20:20

CWE-290

GitHub_M

www.cve.org

cve-2021-29441

authentication bypass

nacos

service discovery

configuration

management

authentication

backdoor

user-agent header spoofing

administrative tasks

CVSS3

8.6

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

AI Score

9.9

Confidence

High

EPSS

0.97

Percentile

99.8%

JSON

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.

CNA Affected

[
  {
    "product": "nacos",
    "vendor": "alibaba",
    "versions": [
      {
        "status": "affected",
        "version": "< 1.4.1"
      }
    ]
  }
]