CVE-2026-27515: Binardat 10g08-0800gsm Auth Bypass Flaw

CVE-2026-27515 Overview

CVE-2026-27515 is a critical session hijacking vulnerability in Binardat 10G08-0800GSM network switch firmware versions prior to V300SP10260209. The web management interface generates predictable numeric session identifiers, allowing remote attackers to guess valid session IDs and hijack authenticated administrator sessions without credentials. This vulnerability is classified under CWE-330 (Use of Insufficiently Random Values).

Critical Impact

Remote attackers can hijack authenticated sessions on the network switch's web management interface, potentially gaining full administrative control over network infrastructure without valid credentials.

Affected Products

• Binardat 10G08-0800GSM Firmware (versions prior to V300SP10260209)
• Binardat 10G08-0800GSM Hardware

Discovery Timeline

• 2026-02-24 - CVE-2026-27515 published to NVD
• 2026-02-25 - Last updated in NVD database

Technical Details for CVE-2026-27515

Vulnerability Analysis

This vulnerability stems from the web management interface's failure to implement cryptographically secure session identifier generation. Instead of using a cryptographically secure pseudo-random number generator (CSPRNG), the firmware generates session IDs using a predictable algorithm that produces sequential or easily guessable numeric values. An attacker with network access to the management interface can enumerate possible session IDs through brute-force techniques or by analyzing the pattern of generated identifiers.

The attack requires no authentication and can be executed remotely over the network. Successful exploitation grants the attacker the same privileges as the hijacked session, which typically includes full administrative access to the network switch. This enables configuration changes, traffic interception capabilities, and potential lateral movement within the network infrastructure.

Root Cause

The root cause is the use of insufficiently random values for session identifier generation (CWE-330). The firmware's web management component relies on a weak pseudo-random number generator or deterministic algorithm to create session tokens. This implementation fails to meet security requirements for session management, where session identifiers must be unpredictable to prevent session hijacking attacks.

Attack Vector

The attack vector is network-based, requiring the attacker to have access to the switch's web management interface. The attack sequence involves:

1. The attacker identifies a Binardat 10G08-0800GSM switch with an accessible web management interface
2. The attacker analyzes the session ID format by obtaining one or more sample session identifiers
3. Using the predictable pattern, the attacker generates candidate session IDs
4. The attacker iterates through candidate session IDs until a valid authenticated session is hijacked
5. Upon successful hijack, the attacker gains the privileges of the legitimate administrator

The vulnerability requires no user interaction and no prior authentication, making it particularly dangerous for switches exposed to untrusted networks.

Detection Methods for CVE-2026-27515

Indicators of Compromise

• Unusual spikes in HTTP requests to the web management interface from unfamiliar IP addresses
• Multiple rapid session validation attempts with sequential or near-sequential session ID values
• Administrative actions occurring from IP addresses not associated with legitimate administrators
• Log entries showing successful authentication followed by session activity from different source IPs

Detection Strategies

• Monitor web management interface access logs for brute-force patterns targeting session endpoints
• Implement network intrusion detection rules to identify high-volume requests to the switch management interface
• Correlate authentication events with subsequent administrative actions to detect session hijacking
• Deploy honeypot session IDs to detect enumeration attempts

Monitoring Recommendations

• Enable verbose logging on the switch web management interface and forward logs to a SIEM
• Configure alerts for administrative actions performed outside normal business hours or from unexpected locations
• Implement network segmentation monitoring to detect unauthorized access attempts to management interfaces
• Regularly audit administrative session logs for anomalies in session creation and usage patterns

How to Mitigate CVE-2026-27515

Immediate Actions Required

• Upgrade Binardat 10G08-0800GSM firmware to version V300SP10260209 or later immediately
• Restrict network access to the web management interface using firewall rules or VLANs
• Implement IP-based access control lists to limit management interface access to trusted administrator workstations
• Consider disabling the web management interface and using alternative management methods (CLI/console) until patching is complete

Patch Information

Binardat has addressed this vulnerability in firmware version V300SP10260209. Organizations should obtain the updated firmware from Binardat's official support channels. For additional technical details, refer to the VulnCheck Advisory on Binardat Switch and the Binardat 10-Gigabit Switch Overview.

Workarounds

• Isolate the management interface on a dedicated out-of-band management network inaccessible from general user networks
• Implement a jump host or bastion server as the sole permitted access point to the switch management interface
• Deploy a web application firewall (WAF) or reverse proxy with rate limiting in front of the management interface
• Enable session timeout policies to minimize the window of opportunity for session hijacking

# Example: Restrict management interface access via firewall (adjust IPs as needed)
# Allow only trusted admin workstation to access switch management interface
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP