{"id":"CVE-2020-5135","kind":"vulnerability","aliases":["CVE-2020-5135"],"related":[],"title":"SonicWall SonicOS: SonicWall SonicOS Buffer Overflow Vulnerability","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.","summary":"A buffer overflow in SonicWall SonicOS, the firewall operating system, lets a remote attacker crash the firewall with a malicious request and possibly run arbitrary code on it. CISA lists it as actively exploited and tags it with ransomware use.","severity":"critical","cvss":9.8,"epss":0.26869,"exploited":true,"exploited_at":"2022-03-15T00:00:00+00:00","products":[{"name":"SonicWall SonicOS","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","firewall","infrastructure","ransomware","self-hosted","sonicos","sonicwall"],"not_affected_if":["default-config"],"how_to_check":"Check the SonicOS version on the firewall management page (unknown which versions are affected in the sources)\nCheck CISA KEV entry for CVE-2020-5135 for vendor advisory link","fix":"Apply the SonicWall SonicOS update that addresses CVE-2020-5135 per vendor instructions (exact fixed version unknown from sources)","status":"open","published_at":"2020-10-12T11:15:12+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:22:19+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:22:19Z","model":"claude-haiku-5-5","output":{"fix":"Apply the SonicWall SonicOS update that addresses CVE-2020-5135 per vendor instructions (exact fixed version unknown from sources)\nunknown","reach":"internet","impact":"high","summary":"A buffer overflow in SonicWall SonicOS, the firewall operating system, lets a remote attacker crash the firewall with a malicious request and possibly run arbitrary code on it. CISA lists it as actively exploited and tags it with ransomware use.","category":"infrastructure","who_cares":["sonicwall","sonicos","firewall","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker runs arbitrary code on the firewall or crashes it remotely","analyst_note":"Find the affected and fixed SonicOS versions and the vendor advisory from the SonicWall PSIRT page, and confirm whether the exposed management or WAN interface is required.","how_to_check":"Check the SonicOS version on the firewall management page (unknown which versions are affected in the sources)\nCheck CISA KEV entry for CVE-2020-5135 for vendor advisory link\nunknown","needs_analyst":true,"not_affected_if":["default-config"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000512,"input_tokens":2855,"output_tokens":454,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2020':9A,12A '-5135':10A,13A '6':99C '6.0.5.3':103C '6.5.1.12':102C '6.5.4':105C '6.5.4.7':101C '7':109C '7.0.0.0':111C 'activ':57B 'affect':96C 'allow':71C 'arbitrari':49B,84C 'attack':38B,74C 'buffer':5A,26B,66C 'caus':76C 'cisa':53B 'code':50B,85C 'crash':39B 'cve':8A,11A 'denial':77C 'dos':80C 'execut':83C 'exploit':16B,58B 'firewal':17B,32B,41B,93C 'gen':98C,108C 'host':22B 'infrastructur':18B 'let':35B 'list':54B 'malici':44B,89C 'oper':33B 'overflow':6A,27B,67C 'possibl':47B 'potenti':82C 'ransomwar':19B,63B 'remot':37B,73C 'request':45B,90C 'run':48B 'self':21B 'self-host':20B 'send':87C 'servic':79C 'sonico':2A,4A,23B,30B,70C,97C 'sonicos':15A 'sonicosv':104C 'sonicwal':1A,3A,24B,29B 'sonicwall':14A 'system':34B 'tag':60B 'use':64B 'v':106C 'version':100C,110C 'vulner':7A,68C,95C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2020-10-12T11:15:12+00:00","kev":{"dateAdded":"2022-03-15","dueDate":"2022-04-05","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Known"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2020-5135","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-5135","severity":null,"published_at":"2022-03-15T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T14:39:40+00:00","note":null},{"source":"epss","external_id":"CVE-2020-5135","url":"https://api.first.org/data/v1/epss?cve=CVE-2020-5135","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2020-5135","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-5135","severity":null,"published_at":"2020-10-12T11:15:12+00:00","modified_at":"2026-06-17T03:20:57+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}