CVE-2021-29441
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=...
Affects 1 product across 1 vendor.
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Mapping is CWE-to-CAPEC per MITRE CAPEC 3.9.
A critical vulnerability in Nacos before version 1.4.1 allows unauthorized access due to a backdoor in the AuthFilter servlet filter, which can bypass authentication checks.
BSID: BS-2021-GLOBAL-248266-C • Model: /workspace/models/qwen2.5-coder-32b-instruct-bf16 • Confidence: HIGH
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| CVE ID | CVE-2021-29441 |
|---|---|
| BSID | BS-2021-GLOBAL-248266-C BreachSpider Global ID |
| CVSS Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Published | 2021-04-27 |
| Last Modified | 2024-11-21 |
| ICS Relevance | 0% |
| Weakness (CWE) | |
| Source | NVD |
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: NIST NVD / MITRE CVE Database
An attacker can exploit this vulnerability by sending specially crafted requests to the Nacos server, which will be processed without proper authentication due to the backdoor in the AuthFilter.
Exploitation Likelihood: CRITICAL
| Vendor | Product | Affected Versions |
|---|---|---|
| Alibaba | Nacos | < 1.4.1 |
No official vendor advisory link on record. See the CVE record →
| CISA known-exploited | Not in KEV catalog |
|---|---|
| Public Exploit | Not confirmed |
| PoC Code | Not confirmed |
AI Enrichment Record — provenance & audit hash
| Model | /workspace/models/qwen2.5-coder-32b-instruct-bf16 |
|---|---|
| Confidence | HIGH |
| Enriched At | 2026-05-24 |
| SHA-512 Audit Hash | 84eb41b676a2f1036d7e6235bcb1cc598dbd36f8e79c97e1ec11f6681cfab14140292cb33212786c9659c6421615c48acfb18c2c8eee5627da87747d12f11188 |
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