Multiple uses of uninitialized variables were found in libopensc that may lead to information disclosure or application crash. An attack requires a crafted USB device or smart card that would present the system with specially crafted responses to the APDUs

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, an attacker with physical access to the computer at the time user or administrator uses a token can cause a stack-buffer-overflow WRITE in card-oberthur. The attack requires crafted USB device or smart card that would present the system with specially crafted responses to the APDUs. This issue has been patched in version 0.27.0.

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, feeding a crafted input to the fuzz_pkcs15_reader harness causes OpenSC to perform an out-of-bounds heap read in the X.509/SPKI handling path. Specifically, sc_pkcs15_pubkey_from_spki_fields() allocates a zero-length buffer and then reads one byte past the end of that allocation. This issue has been patched in version 0.27.0.

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, an attacker with physical access to the computer at the time user or administrator uses a token can cause a stack-buffer-overflow write in GET RESPONSE. The attack requires crafted USB device or smart card that would present the system with specially crafted responses to the APDUs. This issue has been patched in version 0.27.0.

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits within the remaining buffer. In cases where the sc_compacttlv_find_tag is provided untrusted data (such as being read from cards/files), attackers may be able to influence it to return out-of-bounds pointers leading to downstream memory corruption when subsequent code tries to dereference the pointer. This issue has been patched in version 0.27.0.