How severe is CVE-2021-20024?

CVE-2021-20024 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2021-20024 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20024?

CVE-2021-20024 affects Sonicwall Switch. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20024?

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-2021-20024 published?

CVE-2021-20024 was published on 2021-07-09 and last updated on 2026-06-17.

CVE-2021-20024

CVE-2021-20024 is a high-severity vulnerability in Sonicwall Switch with a CVSS 3.x base score of 8.1. 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-125.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Sonicwall Switch
Published: 2021-07-09
Last modified: 2026-06-17

Description

Multiple Out-of-Bound read vulnerability in SonicWall Switch when handling LLDP Protocol allows an attacker to cause a system instability or potentially read sensitive information from the memory locations.

Frequently asked questions

What is CVE-2021-20024?: Multiple Out-of-Bound read vulnerability in SonicWall Switch when handling LLDP Protocol allows an attacker to cause a system instability or potentially read sensitive information from the memory locations.
How severe is CVE-2021-20024?: CVE-2021-20024 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2021-20024 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20024?: CVE-2021-20024 affects Sonicwall Switch. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20024?: 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-2021-20024 published?: CVE-2021-20024 was published on 2021-07-09 and last updated on 2026-06-17.

References

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0011

Affected products (1)

cpe:2.3:o:sonicwall:switch:*:*:*:*:*:*:*:*

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →