Nginx Controller
CVE-2021-23021
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V13 - Configuration Permission assignment review
|
| Impact | CVSS score of 5.5 (MEDIUM). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required. |
| Exploit ScenarioDerived | A local attacker with access to the system could access resources due to misconfigured permissions. |
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Alert meAnalysisAI
The Nginx Controller 3.x before 3.7.0 agent configuration file /etc/controller-agent/agent.conf is world readable with current permission bits set to 644. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Review and restrict file/resource permissions, apply principle of least privilege.
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Technical ContextAI · show details
This vulnerability is classified as Incorrect Permission Assignment (CWE-732), which allows attackers to access resources due to misconfigured permissions. The Nginx Controller 3.x before 3.7.0 agent configuration file /etc/controller-agent/agent.conf is world readable with current permission bits set to 644. Affected products include: F5 Nginx Controller. Version information: before 3.7.0.
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Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
The Nginx Controller 3.x before 3.7.0 agent configuration file /etc/controller-agent/agent.conf is world readable with current permission bits set to 644.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)NVD
More in Nginx Controller
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In NGINX Controller 3.3.0-3.4.0, undisclosed API endpoints may allow for a reflected Cross Site Scripting (XSS) attack.
In versions 3.0.0-3.4.0, 2.0.0-2.9.0, and 1.0.1, there is insufficient cross-site request forgery (CSRF) protections for
In NGINX Controller versions prior to 3.2.0, an unauthenticated attacker with network access to the Controller API can c
On versions 3.0.0-3.3.0, the NGINX Controller webserver does not invalidate the server-side session token after users lo
In versions prior to 3.3.0, the NGINX Controller Agent installer script 'install.sh' uses HTTP instead of HTTPS to check
The NGINX Controller 2.0.0 thru 2.9.0 and 3.x before 3.15.0 Administrator password may be exposed in the systemd.txt fil
In NGINX Controller 3.0.0-3.4.0, recovery code required to change a user's password is transmitted and stored in the dat
On NGINX Controller versions 3.1.0-3.3.0, AVRD uses world-readable and world-writable permissions on its socket, which a
In versions 3.0.0-3.5.0, 2.0.0-2.9.0, and 1.0.1, the Neural Autonomic Transport System (NATS) messaging services in use
Intra-cluster communication does not use TLS. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable
In versions of NGINX Controller prior to 3.2.0, communication between NGINX Controller and NGINX Plus instances skip TLS
GitHub PoC
Exploit-DB