Remote packet triggers access-violation crash in bf4_server_final.exe

Severity: High — Remote crash causing service termination and restart
Affected Component: bf4_server_final.exe (dedicated server process)
Impact: Remote unauthenticated actors can send network packets that cause the server process to write to invalid memory and crash. Multiple servers experience daily crashes and forced restarts.
Description:
A crafted network packet causes bf4_server_final.exe to dereference or write invalid memory, resulting in an unhandled EXCEPTION_ACCESS_VIOLATION (0xC0000005) and process termination. This issue has been exploited repeatedly in the wild and has persisted for over a year. I do not have crash dumps, PCAPs, or server logs to attach.

Observed Symptom:
The server process terminates with an access violation. The only local log entry observed by server operators is a generic crash line indicating an unhandled exception in bf4_server_final.exe (EXCEPTION_ACCESS_VIOLATION). No additional artifacts are currently available from my side.

Reason for Reporting Despite No Artifacts:
The exploit causes persistent denial of service for community servers and appears to be actively exploited daily. Since vendor patching is unlikely for an older title, vendor investigation is needed to identify the vulnerable packet parsing path and provide a patch or mitigation.

Requested Actions for EA Security / Engineering Team:
Review server-side logs and Windows Error Reporting for the crash signature (EXCEPTION_ACCESS_VIOLATION) in bf4_server_final.exe and correlate crashes across servers.
Enable or collect full crash dumps for bf4_server_final.exe (use procdump -e -ma or configure WER) and preserve recent dumps for analysis.

Capture network traffic at the server edge or on a mirror port for the BF4 server port during peak times and preserve PCAPs that overlap crash timestamps.

If reproducible in-house, run the server in an isolated test environment and attempt to reproduce with packet replay from captured traffic.

If a fix is not planned, provide guidance on recommended mitigations (packet normalization proxy, rate limits, temporary firewall filters) that server operators can apply.
 
Start packet capture on the host or at a mirrored port:
# Linux example (adjust interface and port)

sudo tcpdump -i eth0 udp port <bf4-port> -w /tmp/bf4_attack.pcap

Start procdump to capture crash dumps on Windows host (run as admin):
# capture full dump when the process crashes

procdump -e -ma -x C:\dumps bf4_server_final.exe

From an isolated attacker host, replay the suspicious packet(s) (from the pcap) using tcpreplay or a custom sender. Observe server crash and confirm the same EXCEPTION_ACCESS_VIOLATION log.
Stop captures and attach the dump + pcap.

Windows — capture crash dumps automatically
# run as Administrator,create dump dir first

mkdir C:\dumps procdump -e -ma -x
C:\dumps bf4_server_final.exe

This will write a full memory dump into C:\dumps when the process throws an unhandled exception.

Linux (capture PCAP at network edge or mirror)
# capture all UDP traffic to bf4 port (replace <bf4-port> and interface)

sudo tcpdump -i eth0 udp port <bf4-port> -w /tmp/bf4_attack.pcap

Correlation — find last packets before crash (using timestamps)
Use Wireshark to open the pcap, sort by time, and look at the packets leading up to the crash timestamp in the server logs.

A remotely triggered memory‑corruption vulnerability in bf4_server_final.exe is actively causing community servers to crash daily (unhandled EXCEPTION_ACCESS_VIOLATION 0xC0000005).

 Because the issue forces process termination and restart, it creates persistent denial-of-service for players, erodes community trust, and imposes continuous operational overhead on server operators.
Even though Battlefield 4 is an older title, the continuing exploitation has measurable negative impacts: degraded player experience, lost revenue on hosted servers, increased support burden, and reputational harm within the community.

Network‑layer mitigations (ipset, rate limiting, proxies, temporary bans) can reduce immediate impact but are stopgaps that do not remove the underlying vulnerability. Relying on mitigations leaves servers in a fragile state and shifts the maintenance burden to operators rather than resolving the root cause.
Providing an official fix or a vetted mitigation would restore stability, reduce repeated incident response costs, and demonstrate responsible stewardship of the game’s ecosystem.

To assist triage, operators can supply crash timestamps, affected server identifiers, and any available PCAPs or dumps if requested. A targeted engineering effort to reproduce the crash (capture dump + packet, analyze in WinDbg, patch input validation) is the most reliable path to long‑term resolution and will have outsized benefit relative to the developer effort required.

Leaving the issue unpatched allows attackers to continue exploiting a known vulnerability, which can damage the game’s reputation, erode player trust, and create negative perceptions of EA’s commitment to the security and stability of its live services.

Even for older titles, providing a targeted fix or mitigation demonstrates responsible stewardship, protects the community, and preserves the longevity of servers that continue to support active players. A limited engineering effort to patch or harden the affected code will yield long-term benefits: reduced incident response, improved server reliability, and a safer, more stable experience for remaining players. Proactive maintenance of legacy titles signals a commitment to quality and security across EA’s portfolio, reinforcing trust with both players and server operators.
 
           Thank you for considering this as a priority for the benefit of players and server operators alike.