{"id":"CVE-2021-20035","published":"2021-09-27T18:15:08Z","modified":"2026-06-17T03:33:11Z","title":"SonicWall SMA100 Appliances OS Command Injection Vulnerability","vendor":"SonicWall","product":"SMA100 Appliances","tier":"core","eol":null,"description":{"text":"Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.","provenance":"source","from":"NVD"},"summary":{"text":"The SonicWall SMA100 Appliances contain an OS command injection flaw in the management interface, caused by improper neutralization of special elements in user input. A remote attacker with valid authentication can inject arbitrary commands, running as the 'nobody' user, which could lead to denial of service.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:20Z"},"cvss":{"score":6.5,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.04406,"percentile":0.91308,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2025-04-16","dueDate":"2025-05-07","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022 ; https://nvd.nist.gov/vuln/detail/CVE-2021-20035","provenance":"source"},"vulncheckKev":{"dateAdded":"2025-04-15","exploitedFirstSeen":"2025-04-15","ransomware":false,"evidence":[{"url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022","date":"2025-04-15"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-04-16"},{"url":"https://arcticwolf.com/resources/blog/credential-access-campaign-targeting-sonicwall-sma-devices-potentially-linked-to-exploitation-of-cve-2021-20035/","date":"2025-04-17"},{"url":"https://cloud.google.com/blog/topics/threat-intelligence/sonicwall-secure-mobile-access-exploitation-overstep-backdoor","date":"2025-07-16"},{"url":"https://fortiguard.fortinet.com/outbreak-alert/sonicwall-sma-attack","date":"2025-07-18"},{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"}],"evidenceTotal":6,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-78","name":"Improper Neutralization of Special Elements used in an OS Command"}],"references":[{"url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022","tags":["Vendor Advisory"]},{"url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20035","tags":["US Government Resource"]}],"techniques":[{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Command Injection","mappingType":"exploitation_technique","evidence":[],"comment":"While this vulnerability was originally considered a denial-of-service issue in 2021, this improper neutralization issue has been exploited in 2025 as a remote code execution vulnerability. After authenticating (either with default credentials or via brute force, password stuffing, or dictionary attacks), an attacker can execute arbitrary commands as a \"nobody\" user.","confidence":"high"},{"id":"T1078","name":"Valid Accounts","tactics":["initial-access","persistence","privilege-escalation","stealth"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Command Injection","mappingType":"exploitation_technique","evidence":[],"comment":"While this vulnerability was originally considered a denial-of-service issue in 2021, this improper neutralization issue has been exploited in 2025 as a remote code execution vulnerability. After authenticating (either with default credentials or via brute force, password stuffing, or dictionary attacks), an attacker can execute arbitrary commands as a \"nobody\" user.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-7498","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-7498","exploited":true,"exploitedSince":"2025-04-16","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1078","T1059"],"provenance":"source"}],"timeline":[{"date":"2021-09-27","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-20035","provenance":"source"},{"date":"2025-04-15","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022","provenance":"source"},{"date":"2025-04-16","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-04-16","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-7498","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":1297},"priority":{"score":60.8,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 562 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":18.26,"detail":"percentile 0.9131"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":4.55,"detail":"base score 6.5"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}