Sonicwall warns of DoS vulnerability in SSLVPN

There is a security gap in the SSLVPN in Sonicwall's firewall operating system, SonicOS. Attackers can cause the firewall to crash and thus provoke a denial of service situation. Sonicwall is providing updates to patch the vulnerability.

Sonicwall has published a security bulletin in which the company warns of the vulnerability. In the “Virtual office interface” of the SonicOS SSLVPN, a so-called null pointer dereference can occur under unspecified circumstances, i.e. the code can attempt to release resources that have already been released again. This usually leads to the software crashing, as in this case – and fortunately cannot be misused to inject and execute malicious code.

Sonicwall: Attacks from the network possible

Attackers can cause this from the network without prior authentication, as Sonicwall explains in the vulnerability description (CVE-2025-32818, CVSS 7.5, risk “high”). The vulnerability improves the updated firmware versions for the affected devices of the Gen7 NSv series, specifically NSv 270, NSv 470, NSv 870, as well as for the Gen7 firewalls TZ270, TZ270W, TZ370, TZ370W, TZ470, TZ470W, TZ570, TZ570W,TZ570P, TZ670, NSa 2700, NSa 3700,NSa 4700, NSa 5700, NSa 6700, NSsp 10700, NSsp 11700, NSsp 13700 and NSsp 15700 in version 7.2.0-7015 and newer and for the TZ80 in version 8.0.1-8017 or newer.

However, SonicOS GEN6 and GEN7 with 7.0.x firmware versions are not affected, the manufacturer explains.

IT managers should not take security vulnerabilities in Sonicwall products lightly, but should install the security updates offered as soon as possible. Attacks on vulnerabilities in Sonicwall devices are becoming known again and again, as was the case last week. Criminals attacked vulnerabilities in the manufacturer's SMA100 series. This became known back in 2021 and updates have been available since then to plug the gap. Apparently, however, some Sonicwall firewall admins are negligent.

(dmk)