PCSC-Lite: Multiple vulnerabilities

Background

PCSC-Lite is a middleware to access a smart card using the SCard API (PC/SC).

Description

The SCardReleaseContext function normally releases resources associated with the given handle (including “cardsList”) and clients should cease using this handle. However, a malicious client can make the daemon invoke SCardReleaseContext and continue issuing other commands that use “cardsList”, resulting in a use-after-free. When SCardReleaseContext is invoked multiple times it additionally results in a double-free of “cardsList”.

Impact

A local attacker could use a malicious client to connect to pcscd’s Unix socket, possibly resulting in a Denial of Service condition or privilege escalation since the daemon is running as root.

Workaround

There is no known workaround at this time.

Resolution

All PCSC-Lite users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=sys-apps/pcsc-lite-1.8.20"