CVE-2013-7098: 
Cisco AnyConnect Secure Client vulnerability analysis and mitigation

OpenConnect VPN client with GnuTLS before version 5.02 contains a heap overflow vulnerability that can be triggered if MTU is increased on reconnection (Infradead Changelog).

The vulnerability is a heap-based buffer overflow that occurs when the MTU (Maximum Transmission Unit) is increased during a VPN connection reconnection attempt. The issue affects OpenConnect VPN client installations using GnuTLS versions prior to 5.02. According to the National Vulnerability Database, this vulnerability has been assigned a CVSS v3.1 Base Score of 9.8 (CRITICAL) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (NVD).

If successfully exploited, this vulnerability could lead to memory corruption and potential arbitrary code execution. The high CVSS score indicates that the vulnerability can result in a complete compromise of the system's confidentiality, integrity, and availability (NVD).

The vulnerability was fixed in OpenConnect version 5.02. Users should upgrade to this version or later to mitigate the risk. The fix prevents the heap overflow condition when MTU is increased during reconnection (Infradead Changelog).