OpenSC is a smart card application that allows reading and writing via PKCS#11.
Chaskiel M Grundman reported that OpenSC uses weak permissions (ADMIN file control information of 00) for the 5015 directory on smart cards and USB crypto tokens running Siemens CardOS M4.
A physically proximate attacker can exploit this vulnerability to change the PIN on a smart card and use it for authentication, leading to privilege escalation.
There is no known workaround at this time.
All OpenSC users should upgrade to the latest version, and then check and update their smart cards:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-libs/opensc-0.11.6"
# pkcs15-tool --test-update
# pkcs15-tool --test-update --update