CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight System (cFS) and a ground station. Prior to 1.4.2, there is a missing bounds check in Crypto_Key_update() (crypto_key_mgmt.c) which allows a remote attacker to trigger a stack-based buffer overflow by supplying a TLV packet with a spoofed length field. The function calculates the number of keys from an attacker-controlled field (pdu_len), which may exceed the static array size (kblk[98]), leading to an out-of-bounds write and potential memory corruption. This vulnerability is fixed in 1.4.2.