CVE-2020-5135

SonicWall SonicOS: Buffer Overflow

As of , CVE-2020-5135 in SonicWall SonicOS is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch this week.

Exploited
Yes: CISA listed it on 15 March 2022
US federal deadline
5 April 202221 days after CISA listed it. US federal civilian agencies must fix it by then.
Used in ransomware campaigns
KnownCISA changed it from Unknown to Known on 21 August 2026.
EPSS score
0.27Higher than 97% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
EPSS when listed
0.20 on 15 March 2022EPSS on the day CISA listed it.
Public exploit
None foundNeither Metasploit nor Exploit-DB lists one.
Fix
No vendor link in CISA's entry

What CISA says to do

Apply updates per vendor instructions.

CISA's required action

What the flaw is

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's 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.

The CVE record's description, from sonicwall

CVE published
12 October 2020
Assigned by
sonicwall
CVSS
9.8 Critical (CVSS 3.1, from CISA-ADP)
CWE-120
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CISA SSVC, exploitation
active
CISA SSVC, automatable
yes
CISA SSVC, technical impact
total

Timeline

  1. The CVE record was published.
  2. CISA added it to its list of exploited vulnerabilities.
  3. The US federal deadline to fix it.
  4. CISA changed its entry. Ransomware use: Unknown to Known.

SonicOS: other exploited entries

VulnerabilityProductOur groupListedDeadlineEPSS
CVE-2024-53704SSLVPN Improper AuthenticationSonicWall SonicOSPatch this weekRansomware use; EPSS 0.950.95
CVE-2024-40766Improper Access ControlSonicWall SonicOSPatch this weekRansomware use0.18

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