CVE-2024-45616 is a vulnerability identified in OpenSC and its associated tools, including the PKCS#11 module, minidriver, and CTK components. The core issue arises from improper handling of response APDU (Application Protocol Data Unit) buffers when communicating with smart cards or USB devices that emulate smart cards. Specifically, the vulnerability is due to the use of an uninitialized variable caused by insufficient control over the response APDU buffer and its length. An attacker capable of presenting a specially crafted USB device or smart card can exploit this flaw by sending malformed APDU responses that trigger the uninitialized variable usage. This can lead to minor impacts on the confidentiality, integrity, or availability of the system, such as information leakage or unexpected behavior in cryptographic operations. The attack vector is physical, requiring the attacker to have direct access to the target system's smart card reader. The attack complexity is high, as crafting the malicious device and responses requires specialized knowledge and hardware. No privileges or user interaction are required, which slightly increases the risk if physical access is obtained. The CVSS v3.1 base score is 3.9, reflecting low severity due to limited impact and high attack complexity. There are currently no known exploits in the wild, and no patches have been published at the time of this report. The vulnerability affects all versions of OpenSC, as indicated by the affectedVersions field. Given OpenSC's role in smart card-based authentication and cryptographic operations, this vulnerability could be leveraged to disrupt or subtly compromise such security mechanisms.

For European organizations, the impact of CVE-2024-45616 is generally low but non-negligible. Organizations relying on OpenSC for smart card authentication, digital signatures, or cryptographic key management could experience minor confidentiality or integrity issues if an attacker gains physical access and uses a crafted device. Potential impacts include unauthorized information disclosure or subtle manipulation of cryptographic operations, which could undermine trust in secure authentication or transaction processes. Availability impacts are also possible but likely limited to localized disruptions. The requirement for physical access and high attack complexity reduces the likelihood of widespread exploitation. However, sectors with high reliance on smart card infrastructure—such as government agencies, financial institutions, and critical infrastructure operators—should be cautious. The vulnerability could be exploited in targeted attacks against high-value assets or personnel. Overall, the threat does not pose a systemic risk but warrants attention in environments where smart card security is critical.

1. Restrict physical access to systems with smart card readers to trusted personnel only, employing physical security controls such as locked rooms and surveillance. 2. Monitor and audit smart card reader interactions to detect anomalous devices or unusual APDU responses. 3. Implement device whitelisting or USB port control policies to prevent unauthorized USB devices from connecting. 4. Stay informed about OpenSC updates and apply patches promptly once they are released to address this vulnerability. 5. Conduct regular security assessments of smart card infrastructure to identify potential weaknesses. 6. Educate users and administrators about the risks of connecting unknown smart cards or USB devices. 7. Consider additional cryptographic validation or integrity checks on APDU responses if feasible within the deployment environment. 8. Use hardware security modules (HSMs) or trusted platform modules (TPMs) to complement smart card security where possible.