Actively exploited vulnerability
SonicWall SonicOS: improper access control flaw under attack
CVE-2024-40766 · SonicWall SonicOS Improper Access Control Vulnerability
What is affected
SonicWall SonicOS is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.
SonicWall SonicOS contains an improper access control vulnerability that could lead to unauthorized resource access and, under certain conditions, may cause the firewall to crash.
What an attacker can do
This is a improper access control flaw. It lets an attacker perform actions or reach data that should be restricted to authorised users.
- How it is reached
- Over the internet or network
- Access the attacker needs
- No account needed
- Does the victim have to do something?
- No, works without the victim doing anything
CISA records this vulnerability as known to be used in ransomware campaigns: attackers use it to get in, then encrypt files and demand payment.
What to do
- At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
- If you administer SonicWall SonicOS at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
- If the product is past its support date and no fix exists, take it off the internet or retire it.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Vendor advisories and fixes
- psirt.global.sonicwall.compsirt.global.sonicwall.com/vuln-detail/SNWLID-2024-0015
- sonicwall.comwww.sonicwall.com/support/notices/gen-7-and-newer-sonicwall-firewalls-sslvpn-recent-threat
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on September 9, 2024, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by September 30, 2024, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 18% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 97% of all scored vulnerabilities.
Its CVSS severity score is 9.8 out of 10 (critical), as recorded in the US National Vulnerability Database.
Technical description
An improper access control vulnerability has been identified in the SonicWall SonicOS management access, potentially leading to unauthorized resource access and in specific conditions, causing the firewall to crash. This issue affects SonicWall Firewall Gen 5 and Gen 6 devices, as well as Gen 7 devices running SonicOS 7.0.1-5035 and older versions.