EUVD-2026-20906
GHSA-q2cw-g735-jvcc
Severity by source
AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
5DescriptionCVE.org
Improper handling of Unicode encoding in SonicWall SMA1000 series appliances allows a remote authenticated SSLVPN admin to bypass AMC TOTP authentication.
AnalysisAI
Remote authenticated SonicWall SMA1000 SSLVPN administrators can bypass AMC TOTP (Time-based One-Time Password) authentication via improper handling of Unicode encoding, allowing high-privileged attackers to achieve authentication bypass on affected appliances. CVSS 6.6 reflects high-privileged requirement (PR:H) and high attack complexity (AC:H), limiting real-world exploitation despite total technical impact. EPSS score of 0.03% (10th percentile) indicates this vulnerability is unlikely to be exploited in widespread automated attacks, suggesting it requires specific attacker knowledge of Unicode encoding techniques and admin-level access.
Technical ContextAI
SonicWall SMA1000 is a secure remote access appliance that uses SSLVPN to provide authenticated access to corporate networks. The vulnerability resides in the AMC (Appliance Management Console) TOTP authentication mechanism, which validates time-based one-time passwords for admin credential verification. The root cause is improper Unicode encoding handling (CWE-176) in the TOTP validation logic, likely allowing an attacker with admin credentials to craft Unicode-encoded payloads that are processed differently by the TOTP parser than by the validation function, creating a discrepancy that permits bypass. This is a character encoding normalization flaw where Unicode homoglyphs or encoding variations circumvent the authentication check without actually knowing or changing the legitimate TOTP seed or algorithm.
RemediationAI
Apply the vendor-released security patch immediately to update SMA1000 appliances beyond versions 12.5.0-02283 and 12.4.3-03245 respectively (exact patched versions referenced in SonicWall advisory SNWLID-2026-0003 at https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2026-0003). Before patching, implement compensating controls: (1) restrict AMC admin access to specific administrative networks via firewall rules - this limits the source IPs from which TOTP bypass can be leveraged, with the trade-off being reduced administrative flexibility for remote access; (2) enforce MFA at the network perimeter (e.g., require additional RADIUS or LDAP factor before SSLVPN admin login) to create a second barrier even if TOTP is bypassed, though this adds latency to admin login workflows; (3) monitor SSLVPN admin session logs for unusual Unicode characters or encoding anomalies in authentication attempts, flagging sessions for manual review. Given the high-privilege requirement, the most practical interim mitigation is network segmentation restricting admin console access to trusted administrative subnets.
Apache Log4j2 contains a critical JNDI injection vulnerability known as 'Log4Shell' that allows unauthenticated remote c
SonicWall SonicOS SSLVPN contains an authentication bypass vulnerability allowing remote attackers to bypass authenticat
Vulnerability in SonicWall SMA100 allow unauthenticated user to gain read-only access to unauthorized resources. Rated h
A vulnerability in the SonicWall Email Security version 10.0.9.x allows an attacker to create an administrative account
SonicWall SMA1000 AMC and CMC contain a pre-authentication deserialization vulnerability allowing unauthenticated remote
SQL injection vulnerability in d4d/statusFilter.php in Plixer Scrutinizer (aka Dell SonicWALL Scrutinizer) before 9.5.2
Server-side request forgery in the SonicWall SMA1000 Appliance Work Place interface lets remote, unauthenticated attacke
Pre-authentication server-side request forgery in the SonicWall SMA1000 secure-access appliance's Work Place interface l
The ViewPoint web application in Dell SonicWALL Global Management System (GMS) before 7.2 SP2, SonicWALL Analyzer before
The MySQL component in Plixer Scrutinizer (aka Dell SonicWALL Scrutinizer) 9.0.1.19899 and earlier has a default passwor
Multiple SQL injection vulnerabilities in Dell SonicWall Scrutinizer 11.0.1 allow remote authenticated users to execute
A SQL-Injection vulnerability in the SonicWall SSLVPN SMA100 product allows a remote unauthenticated attacker to perform
Same weakness CWE-176 – Improper Handling of Unicode Encoding
View allSame technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today