A vulnerability was found in OpenSC. This issue causes a buffer overrun in the pkcs15 cardos_have_verifyrc_package. This flaw allows an attacker to supply a smart card package with a malformed ASN1 context. The cardos_have_verifyrc_package function scans the ASN1 buffer for two tags, where the remaining length is wrongly calculated due to a moved starting pointer, leading to a possible heap-based buffer out-of-bounds read. In cases where ASN is enabled while compiling, this problem causes a crash, and further information leaks or more damage is likely.