CVE-2020-5135
SonicWall SonicOS Buffer Overflow Vulnerability
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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 15 March 2022. US federal agencies were required to remediate it by 5 April 2022. CISA records this vulnerability as known to be used in ransomware campaigns.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 26.9%, which is higher than 98% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2020-5135 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2020-5135.
What does CVE-2020-5135 affect?
CVE-2020-5135 affects 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.
How severe is CVE-2020-5135?
CVE-2020-5135 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 26.9%, higher than 98% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 5 April 2022.
How should organisations respond to CVE-2020-5135?
Apply the vendor patch for SonicWall SonicOS as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.