CVE-2023-40660: Improper Authentication
A flaw was found in OpenSC packages that allow a potential PIN bypass. When a token/card is authenticated by one process, it can perform cryptographic operations in other processes when an empty zero-length pin is passed. This issue poses a security risk, particularly for OS logon/screen unlock and for small, permanently connected tokens to computers. Additionally, the token can internally track login status. This flaw allows an attacker to gain unauthorized access, carry out malicious actions, or compromise the system without the user's awareness.
AI Analysis
Technical Summary
CVE-2023-40660 is a security vulnerability identified in OpenSC packages, specifically version 0.17.0, which facilitates a PIN bypass attack. OpenSC is widely used for interfacing with smart cards and security tokens, commonly employed for cryptographic operations such as authentication and digital signing. The flaw arises because once a token or smart card is authenticated by one process, other processes can reuse the authenticated state by submitting an empty zero-length PIN, effectively bypassing the PIN verification step. This improper authentication mechanism allows unauthorized processes to perform cryptographic operations without revalidating the user’s PIN. The vulnerability is particularly critical in scenarios where tokens are used for OS logon or screen unlock, as it undermines the security boundary intended to protect user sessions. Additionally, small tokens that remain permanently connected to computers are at risk since the token internally tracks login status, enabling attackers to exploit this state to gain unauthorized access or execute malicious actions stealthily. The CVSS 3.1 score of 6.6 reflects a medium severity, with the vector indicating that the attack requires physical proximity (AV:P), low attack complexity (AC:L), no privileges (PR:N), and user interaction (UI:R). Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk to environments relying on OpenSC for secure authentication. The lack of available patches at the time of disclosure necessitates immediate attention to mitigate potential exploitation.
Potential Impact
For European organizations, the impact of CVE-2023-40660 can be substantial, particularly in sectors that rely heavily on smart card authentication such as government agencies, financial institutions, healthcare, and critical infrastructure. Unauthorized access via PIN bypass can lead to compromise of user credentials, unauthorized cryptographic operations, and potential lateral movement within networks. This can result in data breaches, disruption of secure access controls, and undermining of trust in authentication mechanisms. Organizations using OpenSC for OS logon or screen unlock are especially vulnerable to session hijacking or privilege escalation attacks. The permanent connection of tokens to endpoints increases the attack surface, potentially allowing attackers to exploit the vulnerability remotely if they gain limited access to the system. The confidentiality, integrity, and availability of sensitive systems and data could be compromised, leading to regulatory and compliance risks under GDPR and other European data protection laws.
Mitigation Recommendations
1. Monitor OpenSC project communications and apply security patches promptly once released to address CVE-2023-40660. 2. Until patches are available, restrict the use of OpenSC tokens for critical authentication tasks such as OS logon or screen unlock where feasible. 3. Implement strict process isolation policies to prevent unauthorized processes from accessing authenticated tokens or smart cards. 4. Enforce multi-factor authentication (MFA) mechanisms that do not solely rely on OpenSC tokens to reduce risk exposure. 5. Audit and monitor systems for unusual cryptographic operations or token usage patterns that may indicate exploitation attempts. 6. Educate users about the risk of leaving tokens permanently connected to endpoints and encourage removal when not in use. 7. Employ endpoint security solutions capable of detecting anomalous process behavior related to token access. 8. Review and harden physical security controls to prevent unauthorized physical access to devices with connected tokens.
Affected Countries
Germany, France, United Kingdom, Netherlands, Belgium, Sweden, Finland, Italy, Spain, Poland
CVE-2023-40660: Improper Authentication
Description
A flaw was found in OpenSC packages that allow a potential PIN bypass. When a token/card is authenticated by one process, it can perform cryptographic operations in other processes when an empty zero-length pin is passed. This issue poses a security risk, particularly for OS logon/screen unlock and for small, permanently connected tokens to computers. Additionally, the token can internally track login status. This flaw allows an attacker to gain unauthorized access, carry out malicious actions, or compromise the system without the user's awareness.
AI-Powered Analysis
Technical Analysis
CVE-2023-40660 is a security vulnerability identified in OpenSC packages, specifically version 0.17.0, which facilitates a PIN bypass attack. OpenSC is widely used for interfacing with smart cards and security tokens, commonly employed for cryptographic operations such as authentication and digital signing. The flaw arises because once a token or smart card is authenticated by one process, other processes can reuse the authenticated state by submitting an empty zero-length PIN, effectively bypassing the PIN verification step. This improper authentication mechanism allows unauthorized processes to perform cryptographic operations without revalidating the user’s PIN. The vulnerability is particularly critical in scenarios where tokens are used for OS logon or screen unlock, as it undermines the security boundary intended to protect user sessions. Additionally, small tokens that remain permanently connected to computers are at risk since the token internally tracks login status, enabling attackers to exploit this state to gain unauthorized access or execute malicious actions stealthily. The CVSS 3.1 score of 6.6 reflects a medium severity, with the vector indicating that the attack requires physical proximity (AV:P), low attack complexity (AC:L), no privileges (PR:N), and user interaction (UI:R). Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk to environments relying on OpenSC for secure authentication. The lack of available patches at the time of disclosure necessitates immediate attention to mitigate potential exploitation.
Potential Impact
For European organizations, the impact of CVE-2023-40660 can be substantial, particularly in sectors that rely heavily on smart card authentication such as government agencies, financial institutions, healthcare, and critical infrastructure. Unauthorized access via PIN bypass can lead to compromise of user credentials, unauthorized cryptographic operations, and potential lateral movement within networks. This can result in data breaches, disruption of secure access controls, and undermining of trust in authentication mechanisms. Organizations using OpenSC for OS logon or screen unlock are especially vulnerable to session hijacking or privilege escalation attacks. The permanent connection of tokens to endpoints increases the attack surface, potentially allowing attackers to exploit the vulnerability remotely if they gain limited access to the system. The confidentiality, integrity, and availability of sensitive systems and data could be compromised, leading to regulatory and compliance risks under GDPR and other European data protection laws.
Mitigation Recommendations
1. Monitor OpenSC project communications and apply security patches promptly once released to address CVE-2023-40660. 2. Until patches are available, restrict the use of OpenSC tokens for critical authentication tasks such as OS logon or screen unlock where feasible. 3. Implement strict process isolation policies to prevent unauthorized processes from accessing authenticated tokens or smart cards. 4. Enforce multi-factor authentication (MFA) mechanisms that do not solely rely on OpenSC tokens to reduce risk exposure. 5. Audit and monitor systems for unusual cryptographic operations or token usage patterns that may indicate exploitation attempts. 6. Educate users about the risk of leaving tokens permanently connected to endpoints and encourage removal when not in use. 7. Employ endpoint security solutions capable of detecting anomalous process behavior related to token access. 8. Review and harden physical security controls to prevent unauthorized physical access to devices with connected tokens.
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Technical Details
- Data Version
- 5.1
- Assigner Short Name
- redhat
- Date Reserved
- 2023-08-18T08:08:53.353Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 68e8557bba0e608b4fb1ee7a
Added to database: 10/10/2025, 12:38:19 AM
Last enriched: 10/10/2025, 12:56:44 AM
Last updated: 10/16/2025, 2:41:51 PM
Views: 3
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