A vulnerbility was found in OpenSC. This security flaw cause a buffer overrun vulnerability in pkcs15 cardos_have_verifyrc_package. The attacker can supply a smart card package with malformed ASN1 context. The cardos_have_verifyrc_package function scans the ASN1 buffer for 2 tags, where remaining length is wrongly caculated due to moved starting pointer. This leads to possible heap-based buffer oob read. In cases where ASAN is enabled while compiling this causes a crash. Further info leak or more damage is possible.