How severe is CVE-2021-21535?

CVE-2021-21535 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-21535 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21535?

CVE-2021-21535 affects Dell Hybrid Client. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21535?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-21535 published?

CVE-2021-21535 was published on 2021-04-30 and last updated on 2026-06-17.

CVE-2021-21535

CVE-2021-21535 is a high-severity vulnerability in Dell Hybrid Client with a CVSS 3.x base score of 7.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: High (CVSS 3.x base score 7.4)
CVSS v2: 7.2
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-306
Affected product: Dell Hybrid Client
Published: 2021-04-30
Last modified: 2026-06-17

Description

Dell Hybrid Client versions prior to 1.5 contain a missing authentication for a critical function vulnerability. A local unauthenticated attacker may exploit this vulnerability in order to gain root level access to the system.

Frequently asked questions

What is CVE-2021-21535?: Dell Hybrid Client versions prior to 1.5 contain a missing authentication for a critical function vulnerability. A local unauthenticated attacker may exploit this vulnerability in order to gain root level access to the system.
How severe is CVE-2021-21535?: CVE-2021-21535 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-21535 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21535?: CVE-2021-21535 affects Dell Hybrid Client. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21535?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21535 published?: CVE-2021-21535 was published on 2021-04-30 and last updated on 2026-06-17.

References

https://www.dell.com/support/kbdoc/en-us/000184667/dsa-2021-071-dell-hybrid-client-security-update-for-multiple-vulnerabilities

Affected products (1)

cpe:2.3:a:dell:hybrid_client:*:*:*:*:*:*:*:*

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