What’s Vulnerable › Vulnerabilities

CVE-2021-21559

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-08 · updated 2026-06-17
• Weakness: CWE-295

Description

Dell EMC NetWorker, versions 18.x, 19.1.x, 19.2.x 19.3.x, 19.4, and 19.4.0.1 contain an Improper Certificate Validation vulnerability in the client (NetWorker Management Console) components which uses SSL encrypted connection in order to communicate with the application server. An unauthenticated attacker in the same network collision domain as the NetWorker Management Console client could potentially exploit this vulnerability to perform man-in-the-middle attacks to intercept and tamper the traffic between the client and the application server.

Affected products

• Dell NetWorker: from 18.1.0.1 before 19.4.0.2 — fixed in 19.4.0.2

How to fix

Upgrade to a fixed version: Dell NetWorker 19.4.0.2. Check the vendor advisory for mitigations.

References

• https://www.dell.com/support/kbdoc/en-us/000186638/dsa-2021-104-dell-emc-networker-security-update-for-multiple-vulnerabilities
• https://www.dell.com/support/kbdoc/en-us/000186638/dsa-2021-104-dell-emc-networker-security-update-for-multiple-vulnerabilities

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