CVE-2018-16421 Explained : Impact and Mitigation

CVE-2018-16421 was published on September 4, 2018, and affects the OpenSC library file card-cac.c before version 0.19.0-rc1. Attackers with manipulated smartcards can exploit multiple buffer overflows, potentially leading to a denial of service or other consequences.

Understanding CVE-2018-16421

What is CVE-2018-16421?

This CVE involves buffer overflows in the function cac_get_serial_nr_from_CUID in the OpenSC library file card-cac.c, allowing attackers to manipulate smartcards and potentially cause a denial of service or other impacts.

The Impact of CVE-2018-16421

The vulnerability could result in a denial of service attack (application crash) or potentially lead to other unidentified consequences.

Technical Details of CVE-2018-16421

Vulnerability Description

Several buffer overflows in handling responses from a CAC Card in libopensc/card-cac.c in OpenSC before 0.19.0-rc1 could be exploited by attackers to cause a denial of service or other impacts.

Affected Systems and Versions

Product: n/a
Vendor: n/a
Versions affected: Before OpenSC version 0.19.0-rc1

Exploitation Mechanism

Attackers can exploit the buffer overflows by supplying crafted smartcards, manipulating the function cac_get_serial_nr_from_CUID.

Mitigation and Prevention

Immediate Steps to Take

Update OpenSC to version 0.19.0-rc1 or later to mitigate the vulnerability.
Monitor for any unusual smartcard behavior that could indicate exploitation.

Long-Term Security Practices

Regularly update software and libraries to the latest versions to patch known vulnerabilities.
Implement strict access controls for smartcard usage to prevent unauthorized access.

Patching and Updates

Refer to vendor advisories such as RHSA-2019:2154 and Debian security updates for patches and guidance on addressing CVE-2018-16421.