CVE-2025-64096 is a stack-based buffer overflow vulnerability identified in NASA's CryptoLib, a software-only implementation of the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP). This protocol secures communications between spacecraft running the core Flight System (cFS) and ground stations. The vulnerability resides in the Crypto_Key_update() function within crypto_key_mgmt.c, where the function processes a TLV (Type-Length-Value) packet. Specifically, the function calculates the number of keys to update based on an attacker-controlled length field (pdu_len) without performing adequate bounds checking against the fixed-size static array kblk[98]. If pdu_len exceeds the array size, this results in an out-of-bounds write on the stack, causing memory corruption. Such corruption can lead to arbitrary code execution, denial of service, or information disclosure. The vulnerability is remotely exploitable over the network with low attack complexity and does not require user interaction, though it requires some privileges (PR:L). The CVSS v3.0 base score is 8.8, indicating high severity with impacts on confidentiality, integrity, and availability. The flaw was fixed in CryptoLib version 1.4.2. No known exploits have been reported in the wild as of publication. Given CryptoLib's role in securing spacecraft communications, exploitation could compromise mission-critical data and control channels between spacecraft and ground stations.

For European organizations, especially those engaged in aerospace, satellite communications, and space research, this vulnerability poses a significant risk. Exploitation could allow attackers to gain unauthorized control over spacecraft communication links, potentially leading to data breaches, manipulation of telemetry or command data, and disruption of space missions. Such impacts could affect national security, scientific research, and commercial satellite operations. The confidentiality breach could expose sensitive mission data, while integrity and availability impacts could jeopardize spacecraft operations and safety. Given the critical nature of space systems and their reliance on secure communication protocols like SDLS-EP, this vulnerability could have cascading effects on dependent infrastructure and services. European space agencies, research institutions, and satellite operators using CryptoLib or similar CCSDS protocol implementations must prioritize remediation to prevent exploitation.

1. Immediate upgrade to CryptoLib version 1.4.2 or later, which contains the patch fixing the bounds check issue in Crypto_Key_update(). 2. Implement strict input validation and sanity checks on all incoming TLV packets to ensure length fields do not exceed expected bounds, even beyond the patched version. 3. Employ network segmentation and strict access controls to limit exposure of spacecraft communication interfaces to trusted entities only. 4. Monitor network traffic for anomalous or malformed TLV packets that could indicate exploitation attempts. 5. Conduct regular security audits and code reviews of cryptographic libraries and communication protocols used in spacecraft systems. 6. Develop incident response plans specific to spacecraft communication compromise scenarios. 7. Collaborate with vendors and space agencies to share threat intelligence and coordinate patch deployment. 8. Consider hardware-based protections or memory safety techniques (e.g., stack canaries, ASLR) in the deployment environment to mitigate exploitation impact.