CVE-2017-6412 in Web Appliance
Summary
by MITRE
In Sophos Web Appliance (SWA) before 4.3.1.2, Session Fixation could occur, aka NSWA-1310.
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Analysis
by VulDB Data Team • 11/09/2025
The Sophos Web Appliance vulnerability identified as CVE-2017-6412 represents a critical session management flaw that affects versions prior to 4.3.1.2. This vulnerability falls under the category of session fixation attacks where an attacker can manipulate session identifiers to hijack user sessions. The issue specifically impacts the web appliance's authentication mechanism, creating a pathway for unauthorized access to protected resources. The vulnerability was classified as NSWA-1310 by Sophos, indicating its severity and the need for immediate remediation. This type of vulnerability directly undermines the fundamental security principle of session isolation and user authentication integrity.
The technical implementation of this session fixation flaw stems from inadequate session identifier handling within the Sophos Web Appliance's authentication framework. When users authenticate to the web appliance, the system fails to properly regenerate session tokens upon successful login, allowing attackers to maintain persistent access through previously established session identifiers. The vulnerability exists in the application layer where session management protocols are not properly enforced, creating a condition where session tokens remain static or predictable across authentication boundaries. This flaw typically manifests when the appliance does not adequately invalidate or rotate session identifiers during the authentication process, leaving sessions vulnerable to exploitation.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential data breaches, privilege escalation, and complete system compromise. An attacker who successfully exploits this session fixation vulnerability can maintain persistent access to the appliance's administrative interfaces and user resources without requiring additional authentication credentials. This creates a persistent threat vector that can remain undetected for extended periods, allowing for data exfiltration, configuration modifications, and potential lateral movement within the network. The vulnerability also impacts the appliance's ability to provide secure web filtering and content control, potentially allowing malicious traffic to bypass security controls.
Organizations utilizing affected Sophos Web Appliance versions should implement immediate mitigations including updating to the patched version 4.3.1.2 or later, which addresses the session fixation vulnerability through proper session token regeneration mechanisms. Network administrators should also consider implementing additional monitoring controls to detect unusual authentication patterns and session behavior that might indicate exploitation attempts. The vulnerability aligns with CWE-384, which specifically addresses session fixation issues in web applications, and maps to ATT&CK technique T1566 for credential access through session hijacking. Security teams should also conduct comprehensive vulnerability assessments to identify any other potential session management weaknesses within their network infrastructure, as this vulnerability may indicate broader authentication security gaps that require remediation.