CVE-2008-3972 in OpenSC
Summary
by MITRE
pkcs15-tool in OpenSC before 0.11.6 does not apply security updates to a smart card unless the card s label matches the "OpenSC" string, which might allow physically proximate attackers to exploit vulnerabilities that the card owner expected were patched, as demonstrated by exploitation of CVE-2008-2235.
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Analysis
by VulDB Data Team • 08/02/2021
The vulnerability identified as CVE-2008-3972 affects the pkcs15-tool component within the OpenSC project, specifically impacting versions prior to 0.11.6. This security flaw represents a critical bypass mechanism that undermines the intended security updates for smart cards, creating a scenario where attackers can exploit outdated vulnerabilities even when security patches have been applied to the system. The vulnerability stems from an overly restrictive validation mechanism that requires smart card labels to exactly match the string "OpenSC" before allowing security updates to be deployed to the device.
The technical implementation of this flaw involves the pkcs15-tool's verification process for smart card update operations. When attempting to apply security patches to a smart card, the tool performs a string comparison against the card's label field, specifically requiring an exact match with "OpenSC". This design decision creates a dangerous assumption that all legitimate OpenSC-managed smart cards will bear this specific label, which is not guaranteed in real-world deployments where cards may be labeled differently for various organizational or operational reasons. The vulnerability operates at the application layer within the cryptographic toolset, affecting the certificate management and key storage capabilities of smart cards that are meant to provide secure authentication and data protection services.
The operational impact of this vulnerability is particularly severe for physically proximate attackers who can access the target smart card. These attackers can exploit the mismatch between the expected label and the actual card label to bypass security updates that should have been applied, leaving the card vulnerable to previously patched exploits such as CVE-2008-2235. This scenario creates a false sense of security for card owners who believe their devices are protected by recent security updates, while simultaneously providing attackers with access to known vulnerabilities that could be used for credential theft, unauthorized access to protected systems, or data breaches. The vulnerability essentially creates a backdoor mechanism where security updates are selectively applied based on an arbitrary label match rather than the actual security posture of the device.
The flaw demonstrates a clear violation of security by design principles and aligns with CWE-20, "Improper Input Validation," where the tool fails to properly validate or sanitize the label field before proceeding with security operations. From an attack perspective, this vulnerability maps to several ATT&CK techniques including T1552.001, "Unsecured Credentials," and T1078.004, "Valid Accounts," as attackers can leverage the bypass to maintain access to systems that should have been secured. The vulnerability also reflects poor access control implementation as defined in CWE-284, where insufficient validation mechanisms allow unauthorized operations to proceed. Organizations using OpenSC for smart card management face significant risk exposure, particularly in environments where physical security controls are inadequate or where attackers can obtain physical access to smart card readers and devices. The recommended mitigation involves updating to OpenSC version 0.11.6 or later, which removes the restrictive label matching requirement and implements proper validation of security update operations regardless of card labeling. Additionally, administrators should conduct thorough inventory assessments to identify affected smart cards and ensure that security updates are properly applied across all devices in their environment, while implementing stronger physical security measures to prevent unauthorized access to smart card readers and devices.