CVE-2026-27753: SODOLA SL902 Auth Bypass Vulnerability

CVE-2026-27753 Overview

CVE-2026-27753 is an authentication weakness in the SODOLA SL902-SWTGW124AS managed network switch. Firmware versions through 200.1.20 fail to enforce account lockout or rate limiting on the web management interface. Remote attackers can submit unlimited login attempts against the device, enabling brute-force and credential stuffing attacks. Successful exploitation grants unauthorized access to switch management functions, including VLAN configuration, port mirroring, and QoS settings. The vulnerability is tracked under [CWE-307: Improper Restriction of Excessive Authentication Attempts].

Critical Impact

Attackers with network access to the management interface can conduct unrestricted password guessing attacks, potentially gaining administrative control of the switch and compromising connected network segments.

Affected Products

• SODOLA SL902-SWTGW124AS hardware switch
• SODOLA SL902-SWTGW124AS firmware versions through 200.1.20
• SODOLA 6-Port 2.5G Easy Web Managed Switch product line

Discovery Timeline

• 2026-02-27 - CVE-2026-27753 published to NVD
• 2026-03-03 - Last updated in NVD database

Technical Details for CVE-2026-27753

Vulnerability Analysis

The SL902-SWTGW124AS web management interface accepts authentication requests without tracking failed attempts. The device does not implement progressive delays, CAPTCHA challenges, or temporary account lockouts after repeated failures. This design omission allows an attacker on the same network as the switch to automate login attempts using credential dictionaries.

The attack is purely network-based and requires no prior authentication or user interaction. Because the switch ships with documented default credentials, brute-force attacks against weak or unchanged passwords succeed in short timeframes. Once authenticated, an attacker controls Layer 2 forwarding, link aggregation, IGMP snooping, and VLAN segmentation on the device.

EPSS data places exploitation probability at 0.053%, reflecting limited public exploit tooling at this time. However, the simplicity of the attack technique means scripted exploitation is trivial to develop.

Root Cause

The firmware authentication handler lacks state tracking for failed login attempts per source IP address or per username. Standard mitigations such as exponential backoff, IP banning, and account lockout thresholds are absent from the management web server logic.

Attack Vector

An attacker with network reachability to the switch management interface, typically TCP port 80 or 443, submits HTTP POST requests to the login endpoint at high volume. Tools such as hydra, patator, or custom scripts can iterate through password lists without triggering any defensive response from the device. Refer to the VulnCheck Security Advisory for further technical context.

No verified public proof-of-concept code is available. The vulnerability mechanism is described in prose only.

Detection Methods for CVE-2026-27753

Indicators of Compromise

• High volume of HTTP POST requests to the switch management login endpoint from a single source IP
• Sequential failed authentication entries in switch logs, if logging is enabled
• Unexpected configuration changes such as new VLANs, modified port settings, or altered admin credentials
• Outbound traffic from the switch management IP to unknown destinations following a suspected compromise

Detection Strategies

• Monitor network flows to switch management interfaces for sustained request rates exceeding normal administrative patterns
• Deploy network intrusion detection signatures that flag repeated HTTP 401 or 403 responses from network device IPs
• Correlate authentication failures across multiple management endpoints to identify lateral brute-force campaigns
• Audit switch configuration baselines on a scheduled basis to detect unauthorized changes

Monitoring Recommendations

• Forward switch syslog data to a centralized SIEM and alert on authentication anomalies
• Track administrative session durations and source IPs accessing the management plane
• Enable SNMP traps for configuration changes and authentication events where supported

How to Mitigate CVE-2026-27753

Immediate Actions Required

• Restrict access to the switch management interface using a dedicated management VLAN or out-of-band network
• Apply firewall access control lists permitting management access only from authorized administrator workstations
• Replace default and weak passwords with high-entropy credentials at least 16 characters in length
• Monitor SODOLA vendor channels for firmware updates addressing the rate limiting deficiency

Patch Information

No vendor patch has been published in the referenced advisories at the time of NVD publication. Review the SODOLA Product Page for firmware release notifications beyond version 200.1.20.

Workarounds

• Place the switch management interface on an isolated network segment unreachable from user VLANs or the internet
• Implement upstream rate limiting on a firewall or load balancer fronting the management interface
• Disable the web management interface when not actively in use and rely on console access for configuration
• Use a jump host with logging and multi-factor authentication as the only authorized path to the management plane

# Example upstream ACL on a managing firewall to restrict and rate-limit access
iptables -A FORWARD -p tcp -d <switch_mgmt_ip> --dport 80 \
  -s <admin_workstation_subnet> -m conntrack --ctstate NEW \
  -m limit --limit 5/minute --limit-burst 10 -j ACCEPT
iptables -A FORWARD -p tcp -d <switch_mgmt_ip> --dport 80 -j DROP