CVE-2025-66037 is a vulnerability affecting OpenSC Project's OpenSC software, which is an open-source tool for smart cards. This vulnerability allows an out-of-bounds heap read when a crafted input is fed into the fuzz_pkcs15_reader harness. Specifically, the vulnerability occurs in the X.509/SPKI handling path where the function sc_pkcs15_pubkey_from_spki_fields() allocates a zero-length buffer and subsequently reads one byte past the end of that allocation. This issue can potentially expose sensitive data and has been patched in version 0.27.0 of OpenSC.
The severity level of this vulnerability is classified as low, with a CVSS score of 3.9 based on the CVSS v3.1 scoring system. This score signifies that while the risk is relatively lower than other vulnerabilities, organizations should still treat it seriously, especially in environments where OpenSC is deployed.
Risk to organizations includes potential data exposure due to the out-of-bounds read. Attackers could leverage this vulnerability under specific circumstances, particularly if they have physical access to the smart card tools. Therefore, organizations should prioritize patching immediately to mitigate any potential risks.
As of the latest updates, there is no public exploit confirmed for this vulnerability, and it is not listed in the Known Exploited Vulnerabilities (KEV) catalog. Nevertheless, the existence of a vulnerability that allows out-of-bounds heap reads should raise concerns for organizations and prompt a review of their security posture regarding OpenSC.
Organizations utilizing OpenSC should ensure they upgrade to version 0.27.0 or later, where this vulnerability has been addressed, to maintain the security and integrity of their systems.
Vulnerability Details
The vulnerability is classified as an out-of-bounds read, specifically identified as CWE-125. The official description highlights the potential for data exposure due to improper handling of input data. The affected product is OpenSC, with the vulnerability affecting all versions prior to vendor patch 0.27.0.
The vulnerability was published on March 30, 2026, after being analyzed for its potential impact. With the CVSS score reflecting a low severity, organizations should still be proactive in their response.
Technical Analysis
The root cause of the vulnerability lies within the handling of input data in the OpenSC software. The attack vector is classified as physical, meaning an attacker must have physical access to the device running OpenSC to exploit this vulnerability. The attack complexity is rated as high, which implies that a skilled attacker would be required to successfully exploit the vulnerability.
In terms of privilege requirements, none are necessary to exploit this vulnerability, as it can be executed without any special permissions. User interaction is also not required, which increases the risk of exploitation if an attacker can access the system.
The impact on confidentiality, integrity, and availability is assessed as low. However, the potential exposure of sensitive data through an out-of-bounds read poses a notable risk, particularly in sensitive environments.
Risk & Impact Analysis
Organizations that deploy OpenSC should be aware of the real-world risk posed by this vulnerability. The potential for data exposure could lead to severe consequences, especially if sensitive information is involved. The blast radius of this vulnerability is limited primarily to users with physical access to the devices running OpenSC, but the implications could be far-reaching if exploited.
Urgency for organizations to address this vulnerability is classified as low. However, it is advisable to incorporate this remediation into the regular patching cycle to ensure that the risk is mitigated effectively.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch 0.27.0 are affected by this vulnerability in OpenSC. Organizations should ensure they upgrade to this version to eliminate the risk associated with the vulnerability.
Mitigation & Remediation
To mitigate this vulnerability, organizations should upgrade OpenSC to version 0.27.0 or later, where the issue has been patched. For those unable to apply the patch immediately, implementing strong access controls and monitoring for unusual behavior can help mitigate potential risks. Regular audits of the system and ensuring the latest security updates are applied can strengthen overall security posture.
Organizations should validate remediation through penetration testing to identify similar weaknesses.
Detection Guidance
Monitoring logs for unusual access patterns or attempts to interact with the fuzz_pkcs15_reader harness can provide early detection of potential exploitation attempts. Behavioral anomalies within the OpenSC environment should be tracked, and any unauthorized changes to the system should be flagged for immediate review.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-66037 lies in its representation of the ongoing challenges in managing open-source software vulnerabilities. As organizations increasingly rely on open-source tools like OpenSC, they must adopt robust vulnerability management practices to reduce exposure.
This vulnerability serves as a reminder for security teams to prioritize regular updates and to maintain vigilance against similar types of vulnerabilities that can arise from input handling errors.
For further insights on vulnerability management, organizations may explore the vulnerability management program design and its importance in maintaining security.
Additionally, the importance of conducting regular penetration testing cannot be overstated, as it helps to uncover and remediate vulnerabilities proactively.
In conclusion, CVE-2025-66037 highlights the need for continual vigilance and proactive security measures in the management of open-source software.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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