SB2022062916 - Multiple vulnerabilities in nats-server
Published: November 6, 2020 Updated: June 30, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Improper access control (CVE-ID: CVE-2020-26892)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
The vulnerability allows a remote attacker to execute arbitrary code on the system.
The vulnerability exists due to improper access restrictions in JWT library in NATS nats-server when handling expired credentials. A remote attacker can send a specially crafted request, gain unauthorized access and execute arbitrary code on the system.
2) NULL pointer dereference (CVE-ID: CVE-2020-26521)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 a NULL pointer dereference error in JWT library in NATS nats-server. A remote attacker can pass specially crafted data and perform a denial of service (DoS) attack.
Remediation
Install update from vendor's website.
References
- https://www.openwall.com/lists/oss-security/2020/11/02/2
- https://github.com/advisories/GHSA-4w5x-x539-ppf5
- https://github.com/nats-io/nats-server/security/advisories/GHSA-2c64-vj8g-vwrq
- http://www.openwall.com/lists/oss-security/2020/11/02/2
- https://github.com/advisories/GHSA-h2fg-54x9-5qhq
- https://github.com/nats-io/nats-server/security/advisories/GHSA-hmm9-r2m2-qg9w