CVE-2025-30216: NASA CryptoLib RCE Vulnerability

CVE-2025-30216 Overview

CVE-2025-30216 is a critical Heap Overflow vulnerability discovered in NASA's CryptoLib, a software-only solution that implements the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between spacecraft running the core Flight System (cFS) and ground stations. The vulnerability exists in the Crypto_TM_ProcessSecurity function within crypto_tm.c at line 1735.

When processing the Secondary Header Length of a Telemetry (TM) protocol packet, if the Secondary Header Length value exceeds the packet's total length, a heap overflow is triggered during the memcpy operation that copies packet data into the dynamically allocated buffer p_new_dec_frame. This allows an attacker to overwrite adjacent heap memory, potentially leading to arbitrary code execution or system instability.

Critical Impact

This vulnerability enables network-based attackers to trigger heap memory corruption in spacecraft-ground communication systems without authentication, potentially leading to arbitrary code execution or complete system instability in critical space infrastructure.

Affected Products

• NASA CryptoLib versions 1.3.3 and prior
• Systems implementing CCSDS SDLS-EP for spacecraft communications
• Core Flight System (cFS) deployments using CryptoLib for security

Discovery Timeline

• 2025-03-25 - CVE-2025-30216 published to NVD
• 2025-05-06 - Last updated in NVD database

Technical Details for CVE-2025-30216

Vulnerability Analysis

This heap overflow vulnerability stems from insufficient validation of the Secondary Header Length field in TM protocol packets. The Crypto_TM_ProcessSecurity function allocates a buffer (p_new_dec_frame) based on expected packet size but fails to properly validate that the Secondary Header Length does not exceed the total packet length before performing memory copy operations.

The vulnerability is particularly severe because it exists in software designed to secure spacecraft communications. A successful exploit could compromise the integrity of space-to-ground communications, potentially allowing attackers to inject malicious commands or disrupt critical telemetry data.

The issue is classified under CWE-122 (Heap-based Buffer Overflow) and CWE-787 (Out-of-bounds Write), reflecting the memory safety violations that occur when an oversized Secondary Header Length value causes writes beyond allocated heap boundaries.

Root Cause

The root cause is improper input validation of the Secondary Header Length field in TM protocol packets. The code fails to verify that this length value falls within acceptable bounds before using it in memory operations. Without validation against both a maximum allowed value and the actual packet length, a maliciously crafted packet can specify a Secondary Header Length that causes the subsequent memcpy operation to overflow the allocated heap buffer.

Attack Vector

An attacker can exploit this vulnerability by sending specially crafted TM protocol packets with an oversized Secondary Header Length value. The attack is network-based and requires no authentication or user interaction. The attacker must be able to send data to a system running the vulnerable CryptoLib implementation, which could be achieved through:

1. Compromising or spoofing ground station communications
2. Man-in-the-middle positioning between spacecraft and ground systems
3. Direct network access to systems processing TM packets

The following patch demonstrates the security fix implemented by NASA:

 #define TM_FRAME_DATA_SIZE 1786 /* bytes */
 #define TM_FILL_SIZE       1145 /* bytes */
 #define TM_PAD_SIZE        2    /* bytes */
+#define TM_SECONDARY_HDR_MAX_VALUE 63
 
 // AOS Defines
 #define AOS_FRAME_DATA_SIZE 1786 /* bytes */

Source: GitHub Code Commit Update

The patch introduces a new constant TM_SECONDARY_HDR_MAX_VALUE set to 63, establishing an upper bound for the Secondary Header Length field.

 #define CRYPTO_LIB_ERR_AOS_FL_LT_MAX_FRAME_SIZE                             (-76)
 #define CRYPTO_LIB_ERR_TM_FL_LT_MAX_FRAME_SIZE                              (-77)
 #define CRYPTO_LIB_ERR_INVALID_FHECF                                        (-78)
+#define CRYPTO_LIB_ERR_TM_SECONDARY_HDR_SIZE                                (-79)
+#define CRYPTO_LIB_ERR_TM_SECONDARY_HDR_VN                                  (-80)
 
-#define CRYPTO_CORE_ERROR_CODES_MAX -78
+#define CRYPTO_CORE_ERROR_CODES_MAX -80
 
 // Define codes for returning MDB Strings, and determining error based on strings
 #define CAM_ERROR_CODES     600

Source: GitHub Code Commit Update

The patch also adds new error codes CRYPTO_LIB_ERR_TM_SECONDARY_HDR_SIZE and CRYPTO_LIB_ERR_TM_SECONDARY_HDR_VN to properly handle and report invalid Secondary Header conditions.

Detection Methods for CVE-2025-30216

Indicators of Compromise

• Unexpected crashes or segmentation faults in processes using CryptoLib TM packet processing
• Memory corruption errors in system logs related to Crypto_TM_ProcessSecurity function
• Anomalous TM packets with Secondary Header Length values exceeding normal bounds (greater than 63 bytes)
• Heap memory corruption patterns detected by memory sanitizers or security monitoring tools

Detection Strategies

• Deploy application-level monitoring for CryptoLib processes to detect abnormal terminations or memory access violations
• Implement network traffic analysis to identify TM packets with anomalous Secondary Header Length values
• Enable heap memory protection mechanisms (ASLR, heap canaries) to detect exploitation attempts
• Monitor for error code -79 (CRYPTO_LIB_ERR_TM_SECONDARY_HDR_SIZE) in patched versions indicating rejected malformed packets

Monitoring Recommendations

• Configure alerting for any process crashes in systems running CryptoLib-based communications
• Implement deep packet inspection for CCSDS protocol traffic to validate TM frame structure
• Enable memory debugging tools in development and testing environments to catch overflow attempts
• Review system logs for repeated invalid packet rejections that may indicate active exploitation attempts

How to Mitigate CVE-2025-30216

Immediate Actions Required

• Update NASA CryptoLib to a version containing commit 810fd66d592c883125272fef123c3240db2f170f or later
• Audit all systems using CryptoLib for TM protocol processing and prioritize patching critical infrastructure
• Implement network segmentation to limit exposure of systems processing spacecraft communications
• Enable additional memory protection mechanisms where possible (stack canaries, ASLR, address sanitizers)

Patch Information

NASA has released a security patch at commit 810fd66d592c883125272fef123c3240db2f170f. The patch introduces proper bounds checking for the TM Secondary Header Length field by defining a maximum value constant (TM_SECONDARY_HDR_MAX_VALUE = 63) and adding corresponding error codes for validation failures. Organizations should apply this patch immediately by updating to the latest CryptoLib version. For detailed information, refer to the GitHub Security Advisory.

Workarounds

• Implement input validation at network boundaries to reject TM packets with Secondary Header Length values exceeding 63 bytes
• Deploy network-level filtering to restrict access to systems processing TM protocol data
• Consider running CryptoLib processes in sandboxed environments to limit impact of potential exploitation
• Implement runtime memory protection tools to detect and prevent heap overflow exploitation

# Configuration example - Building CryptoLib with security hardening flags
git clone https://github.com/nasa/CryptoLib.git
cd CryptoLib
git checkout 810fd66d592c883125272fef123c3240db2f170f
# Build with memory safety flags
cmake -DCMAKE_C_FLAGS="-fstack-protector-strong -D_FORTIFY_SOURCE=2" ..
make