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CVE-2021-20043SonicWall SMA100 Heap Buffer Overflow

A Heap-based buffer overflow vulnerability in SonicWall SMA100 getBookmarks method allows a remote authenticated attacker to potentially execute code as the nobody user in the appliance.

Published Jan 4, 2022 · Updated Aug 3, 2024

Key Facts

Patch in the next maintenance window
  • CVE-2021-20043 is a high-severity vulnerability (CVSS 8.8 v3.1) affecting Sma 200 Firmware (Sonicwall), Sma 210 Firmware (Sonicwall), Sma 400 Firmware (Sonicwall) and 3 more products.
  • It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
  • EPSS estimates a 23% probability of exploitation in the next 30 days.
  • No fixed version is listed yet; check the vendor advisory for mitigations.
  • Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.

Scores

CVSS v3.1

8.8

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS (30-day exploit likelihood)

23%

Higher than 97.7% of all scored CVEs

Exploit maturity

None known

ATLAS score

37/100

Publication score, see How it works

Exploitation Verdict

KEV listed

Not listed

Federal due date

None

No federal due date

Ransomware use

Not reported

Attributed actors

None named

Exploit & Defence Guidance

Exploit maturity

None known

Public exploit code

0

Proof-of-concept links

In-the-wild evidence

0

Reports of active use

Description

A Heap-based buffer overflow vulnerability in SonicWall SMA100 getBookmarks method allows a remote authenticated attacker to potentially execute code as the nobody user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

Affected Products

11 affected entries in total
ProductAffected versionsFixed in
Sma 200 FirmwareSonicwall10.2.0.8-37sv, 10.2.1.1-19svn/a
Sma 210 FirmwareSonicwall10.2.0.8-37sv, 10.2.1.1-19svn/a
Sma 400 FirmwareSonicwall10.2.0.8-37sv, 10.2.1.1-19svn/a
Sma 410 FirmwareSonicwall10.2.0.8-37sv, 10.2.1.1-19svn/a
Sma 500v FirmwareSonicwall10.2.0.8-37sv, 10.2.1.1-19svn/a
1 more affected products in the full CVE brief

Timeline

  1. Publicly disclosed

    Jan 4, 2022

  2. Last updated

    Aug 3, 2024

Weakness Type

  • CWE-122 Heap-based Buffer Overflow
  • CWE-787 Out-of-bounds Write

FAQ

Common Questions.

Is CVE-2021-20043 On Your Attack Surface?

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Figures as of Oct 19, 2026. Compiled by Brandefense technologies from public vulnerability catalogs; scoring as described in How it works.

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