CVE-2018-16424

Vulnerability

A double free vulnerability exists in the read_file function in tools/egk-tool.c in OpenSC versions before 0.19.0-rc1. The issue occurs when handling responses from smartcards. An attacker can supply a crafted smartcard that triggers a double free, leading to memory corruption [1].

Exploitation

To exploit, an attacker needs physical access to the system to insert a malicious smartcard, or the ability to emulate a smartcard via a card reader. The attacker crafts a smartcard that sends a specially malformed response to APDU commands processed by the read_file function. No authentication is required; the vulnerability is triggered during normal card interaction [1].

Impact

Successful exploitation can cause a denial of service via application crash. The description also mentions "possibly have unspecified other impact," which could include arbitrary code execution, though this is not confirmed in available references [1].

Mitigation

The vulnerability is fixed in OpenSC version 0.19.0-rc1, released on 2018-09-04 [3]. Users should upgrade to this version or later. No workarounds are documented; as a general precaution, only use smartcards from trusted sources [1].