CVE-2023-32275 in VPN
Summary
by MITRE • 10/25/2023
An information disclosure vulnerability exists in the CtEnumCa() functionality of SoftEther VPN 4.41-9782-beta and 5.01.9674. Specially crafted network packets can lead to a disclosure of sensitive information. An attacker can send packets to trigger this vulnerability.
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Analysis
by VulDB Data Team • 10/31/2023
The CVE-2023-32275 vulnerability represents a critical information disclosure flaw within the SoftEther VPN software ecosystem, specifically affecting versions 4.41-9782-beta and 5.01.9674. This vulnerability resides within the CtEnumCa() function, which is responsible for enumerating certificate authorities within the VPN infrastructure. The flaw allows malicious actors to exploit specially crafted network packets to extract sensitive information from the affected systems, potentially compromising the entire VPN infrastructure's security posture. The vulnerability's impact extends beyond simple data exposure as it fundamentally undermines the trust model that VPN solutions rely upon for secure communications.
The technical implementation of this vulnerability stems from inadequate input validation and memory handling within the CtEnumCa() function. When processing network packets containing malformed or crafted data, the function fails to properly sanitize inputs before using them in memory operations. This insufficient validation creates a pathway for attackers to manipulate the function's behavior and extract information from memory locations that should remain protected. The vulnerability aligns with CWE-20, which describes improper input validation, and CWE-215, which addresses information exposure through improper error handling. The attack vector requires only network-level access to trigger the vulnerability, making it particularly dangerous as it can be exploited remotely without requiring physical access or elevated privileges.
The operational impact of CVE-2023-32275 is severe and multifaceted, potentially exposing certificate authorities, private keys, and other sensitive cryptographic material that forms the backbone of VPN security. Attackers who successfully exploit this vulnerability could gain access to the entire certificate management system, allowing them to impersonate legitimate users or even create fraudulent certificates for unauthorized access. This information disclosure could enable further attacks within the network, including man-in-the-middle attacks, credential theft, and privilege escalation. The vulnerability also poses risks to compliance requirements, as the exposure of cryptographic material could violate regulations such as those outlined in the NIST SP 800-57 standard for cryptographic key management and the PCI DSS requirements for secure handling of sensitive data.
Organizations utilizing affected SoftEther VPN versions should immediately implement mitigations including network segmentation to limit access to VPN servers, deployment of intrusion detection systems to monitor for exploitation attempts, and implementation of network access controls to restrict which systems can communicate with VPN infrastructure. The recommended approach includes applying vendor patches as soon as they become available, implementing strict input validation at network boundaries, and conducting thorough security assessments of all VPN-related systems. Additionally, organizations should consider implementing certificate monitoring solutions to detect unauthorized certificate issuance and establish incident response procedures specifically tailored to VPN security incidents. The vulnerability's classification under the MITRE ATT&CK framework places it within the information gathering and credential access domains, specifically mapping to techniques such as credential dumping and reconnaissance activities that threat actors frequently employ to establish persistent access to network environments.