CVE-2010-3902 in OpenConnect
Summary
by MITRE
OpenConnect before 2.26 places the webvpn cookie value in the debugging output, which might allow remote attackers to obtain sensitive information by reading this output, as demonstrated by output posted to the public openconnect-devel mailing list.
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Analysis
by VulDB Data Team • 09/27/2021
The vulnerability described in CVE-2010-3902 represents a critical information disclosure issue within the OpenConnect VPN client software. This flaw affects versions prior to 2.26 and stems from improper handling of sensitive data during debugging operations. The vulnerability specifically manifests when the webvpn cookie value is included in debugging output, creating an avenue for remote attackers to gain access to confidential information that should remain protected. The security implications are particularly severe because the debugging output was being published to a public mailing list, making the sensitive cookie data immediately accessible to any observer with network access.
The technical root cause of this vulnerability aligns with CWE-200, which defines information exposure weaknesses in software systems. The flaw occurs during the debugging process where the application fails to sanitize or filter sensitive authentication tokens before logging them to output streams. The webvpn cookie contains authentication credentials that are essential for maintaining secure access to VPN resources, and when this information appears in debugging output, it creates a direct pathway for credential compromise. This issue demonstrates poor input validation and output sanitization practices within the OpenConnect application's debugging framework.
From an operational perspective, this vulnerability presents significant risks to organizations relying on OpenConnect for secure remote access. Attackers can exploit this weakness by simply monitoring the public openconnect-devel mailing list to obtain the webvpn cookie values, which can then be used to impersonate legitimate users and gain unauthorized access to protected network resources. The impact extends beyond immediate credential theft to potential lateral movement within networks, as the compromised cookie values may grant access to additional systems and services that rely on the same authentication mechanisms. This vulnerability undermines the fundamental security assumptions of the VPN infrastructure and creates persistent access points for malicious actors.
The mitigation strategy for this vulnerability involves upgrading to OpenConnect version 2.26 or later, which implements proper sanitization of debugging output to prevent sensitive information disclosure. Organizations should also implement comprehensive logging policies that ensure debugging information does not contain authentication tokens or other sensitive data. Security practitioners should conduct regular audits of application logging mechanisms to verify that sensitive information is properly filtered from output streams. Additionally, network monitoring solutions should be configured to detect and alert on suspicious patterns in public mailing list posts or other publicly accessible channels that might contain leaked authentication information. This vulnerability highlights the importance of following security best practices for debugging output management and aligns with ATT&CK technique T1567.002, which covers "Exfiltration Over Web Service" through the unauthorized access to sensitive data through publicly exposed channels. The remediation process should include comprehensive security testing of logging mechanisms and implementation of automated tools to scan for sensitive data in debug output before publication.