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Vulnerabilities

Vulnerability · CVE-2020-5135

SonicWall SonicOS Buffer Overflow Vulnerability

Published Oct 12, 2020 · catalog updated Jun 16, 2026 · SonicWall SonicOS

Patch now

CVE-2020-5135 is in the CISA known-exploited catalog, due Apr 5, 2022. Confirm SonicWall SonicOS against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Severity
Critical9.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
26.87%
Remediation
Remediation guidance
Affected products
cpe sonicwall/sonicos · cpe sonicwall/sonicosv · vendor SonicWall SonicOS

A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe sonicwall/sonicos7.0.0.0
  • cpe sonicwall/sonicosvversion unspecified
  • vendor SonicWall SonicOSversion unspecified

How to fix CVE-2020-5135

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2020-5135 is in the CISA known-exploited catalog, due Apr 5, 2022. Confirm SonicWall SonicOS against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Compare what you have installed with 7.0.0.0. Apply updates per vendor instructions.

What should an analyst verify?

CWE-120: Classic Buffer Overflow. EPSS 26.87%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 12, 2020 · Catalog

    Detected

    A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.

  2. Mar 15, 2022 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Apr 5, 2022 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Jun 16, 2026 · Catalog

    Updated

    A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.

Sources

  • CISA KEVConfirmed exploitationCVE-2020-5135

    A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2020-5135

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2020-5135

    30-day exploitation probability 26.9%

    first.org
  • NIST NVDVulnerability recordCVE-2020-5135

    A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2020-5135

    A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.