CVE-2023-0656
HighCVSS 7.5Exploitation Probability (EPSS)
Very high risk99th percentile - higher than 99% of all known CVEs
Summary
A stack-based buffer overflow vulnerability in SonicOS allows a remote unauthenticated attacker to cause Denial of Service (DoS), which could cause an impacted firewall to crash.
Risk Assessment
This can make the firewall unavailable and interrupt network protection.
Recommendation
Update SonicOS firmware to a patched version.
Other vulnerabilities in SonicOS
See all- CVE-2026-19868HighActively exploited
An authentication enforcement vulnerability in the SonicOS SSLVPN service may allow a user with valid credentials for an alternate authentication method to bypass SAML authentication controls. Successful exploitation may also bypass SAML-enforced multi-factor authentication (MFA).
- CVE-2025-40600Critical
Use of an externally-controlled format string vulnerability in the SonicOS SSL VPN interface allows a remote unauthenticated attacker to cause service disruption.
- CVE-2024-22394Critical
An improper authentication vulnerability has been identified in the SonicWall SonicOS SSL-VPN feature, which under specific conditions could allow a remote attacker to bypass authentication. This issue affects only firmware version SonicOS 7.1.1-7040.
- CVE-2022-22274Critical
A stack-based buffer overflow vulnerability in SonicOS triggered via HTTP request allows a remote unauthenticated attacker to cause Denial of Service (DoS) or potentially result in code execution in the firewall.
- CVE-2021-20031Medium
A Host Header Redirection vulnerability exists in SonicOS. A remote attacker could potentially redirect firewall management users to arbitrary web domains.
- CVE-2020-5135CriticalActively exploited
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. It affects SonicOS Gen 6 versions 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.
- CVE-2026-82308High
A pre-authentication heap-based buffer overflow vulnerability was identified in the SonicOS SSL-VPN service. It could allow a remote unauthenticated attacker to cause an application-level denial of service.
- CVE-2026-77709Medium
A pre-authentication heap-based buffer overflow vulnerability was identified in the SonicOS TACACS+ authentication client. Under specific conditions it could allow a remote unauthenticated attacker to cause an application-level denial of service.
- CVE-2026-77708Medium
A pre-authentication stack-based buffer overflow vulnerability was identified in the SonicOS TACACS+ authentication client. Under specific conditions it could allow a remote unauthenticated attacker to cause an application-level denial of service.
- CVE-2026-19703Medium
A weak password hashing vulnerability has been identified on SonicOS virtual appliances. Under specific conditions, an attacker with existing local access could disclose a platform credential that grants access to a limited subset of platform settings.
Original NVD description (English source)
A Stack-based buffer overflow vulnerability in the SonicOS allows a remote unauthenticated attacker to cause Denial of Service (DoS), which could cause an impacted firewall to crash.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS