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. In versions 1.3.3 and prior, an unsigned integer underflow in the `Crypto_TC_ProcessSecurity` function of CryptoLib leads to a heap buffer overflow. The vulnerability is triggered when the `fl` (frame length) field in a Telecommand (TC) packet is set to 0. This underflow causes the frame length to be interpreted as 65535, resulting in out-of-bounds memory access. This critical vulnerability can be exploited to cause a denial of service (DoS) or potentially achieve remote code execution. Users of CryptoLib are advised to apply the recommended patch or avoid processing untrusted TC packets until a fix is available.

AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CWE-122

CWE-191

https://github.com/nasa/CryptoLib/commit/ca39cb96f21e76102aefb956d2c8c0ba0bd143ca

https://github.com/nasa/CryptoLib/security/advisories/GHSA-3f5x-r59x-p8cf