CVE-2010-4523 in opensc
Summary
by MITRE
Multiple stack-based buffer overflows in libopensc in OpenSC 0.11.13 and earlier allow physically proximate attackers to execute arbitrary code via a long serial-number field on a smart card, related to (1) card-acos5.c, (2) card-atrust-acos.c, and (3) card-starcos.c.
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Analysis
by VulDB Data Team • 05/26/2025
The vulnerability CVE-2010-4523 represents a critical stack-based buffer overflow in the OpenSC project's libopensc library affecting versions 0.11.13 and earlier. This flaw exists within the smart card card driver implementations, specifically in three distinct modules: card-acos5.c, card-atrust-acos.c, and card-starcos.c. The vulnerability is classified as a stack-based buffer overflow under CWE-121, which occurs when a program writes data beyond the boundaries of a fixed-length stack buffer, potentially corrupting adjacent memory locations. The attack vector requires physical proximity to the target system, making this a local privilege escalation vulnerability that can be exploited by attackers who have direct access to the smart card reader and can manipulate the card's serial number field.
The technical implementation of this vulnerability stems from inadequate input validation within the smart card communication protocols. When the libopensc library processes smart card data, it fails to properly validate the length of the serial-number field received from the card. The card-acos5.c, card-atrust-acos.c, and card-starcos.c modules all contain similar code patterns where they directly copy or process serial number data without bounds checking, leading to stack corruption when an attacker provides a serial number exceeding the allocated buffer space. This flaw allows attackers to overwrite return addresses, function pointers, and other critical stack data, enabling arbitrary code execution with the privileges of the process running the OpenSC library.
From an operational perspective, this vulnerability poses significant risks to systems utilizing smart card authentication, particularly in environments where physical security is compromised or where attackers can gain proximity to target systems. The attack requires only physical access to the smart card reader and the ability to manipulate card data, making it particularly dangerous in corporate, government, or financial environments where smart cards are used for authentication and access control. The impact extends beyond simple code execution to potentially allow attackers to bypass authentication mechanisms, escalate privileges, or gain unauthorized access to protected systems. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation could enable attackers to execute malicious code within the context of the smart card reader application.
The exploitation of this vulnerability can be mitigated through several approaches that align with established security practices. The primary remediation involves updating to OpenSC versions 0.11.14 or later, where the buffer overflow has been patched through proper input validation and bounds checking implementations. Additionally, system administrators should implement proper access controls to limit physical access to smart card readers and ensure that only authorized personnel can interact with these devices. Network segmentation and monitoring should be implemented to detect anomalous smart card communication patterns that might indicate exploitation attempts. Organizations should also consider implementing hardware security modules or alternative authentication methods that do not rely on vulnerable smart card protocols, following the principle of least privilege and defense in depth strategies recommended by NIST SP 800-53. The vulnerability demonstrates the importance of secure coding practices and input validation, particularly in cryptographic libraries that handle sensitive data from external devices.