SB2021030701 - Multiple vulnerabilities in nats-server

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Main Vulnerability Database SB2021030701

SB2021030701 - Multiple vulnerabilities in nats-server

Published: March 7, 2021 Updated: June 30, 2026

Security Bulletin ID SB2021030701
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Resource exhaustion (CVE-ID: CVE-2020-28466)

CWE-ID: CWE-400 - Resource exhaustion

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources. A remote attacker can perform a denial of service attack using configs that represent a service export/import cycles.


2) Missing Authorization (CVE-ID: CVE-2021-3127)

CWE-ID: CWE-862 - Missing Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to access subjects from another account.

The vulnerability exists due to improper access control in import token permission checking when processing tampered account JWTs with import tokens. A remote user can upload a tampered account JWT that reuses an import token from another account to access subjects from the exporting account.

Exploitation requires deployments where untrusted accounts are able to update the account server with imports, and private exports are in use.


Remediation

Install update from vendor's website.

References