# CVE-2020-5135: SonicWall SonicOS Buffer Overflow Vulnerability > CVE-2020-5135: SonicWall SonicOS Buffer Overflow Vulnerability. CVSS 9.8 (CVSS 3.1), in CISA KEV. Canonical: https://rewindex.com/cve/CVE-2020-5135 Last updated: 2025-10-21T23:35:35Z - Published: 2020-10-12 10:40 UTC · Updated: 2025-10-21 23:35 UTC · Assigner: sonicwall - CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS: 26.9%, 98th percentile (scored 2026-10-25) - CISA KEV: yes, added 2022-03-15, federal due date 2022-04-05, ransomware use: Known - CWE: CWE-120 ## Description 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. ## CISA required action Apply updates per vendor instructions. ## Affected vendors and products - SonicWall: SonicOS ## References - [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2020-5135) - [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2020-5135) - [https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2020-0010](https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2020-0010) --- _Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_ --- Canonical: https://rewindex.com/cve/CVE-2020-5135 · Markdown: https://rewindex.com/cve/CVE-2020-5135.md · JSON: https://rewindex.com/api/v1/cves/CVE-2020-5135 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:03:27.475Z