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How CVE-2025-47294 Works
The vulnerability stems from an integer overflow/wraparound in FortiOS versions 7.2.0–7.2.7 and 7.0.0–7.0.14. When processing a maliciously crafted request, the `csfd` daemon fails to properly validate integer calculations, leading to a memory corruption. Attackers can exploit this by sending a specially designed payload, causing the daemon to crash and trigger a denial-of-service (DoS) condition. The flaw resides in packet parsing logic, where unchecked arithmetic operations allow buffer underflows/overflows, destabilizing the system.
DailyCVE Form
Platform: Fortinet FortiOS
Version: 7.2.0–7.2.7, 7.0.0–7.0.14
Vulnerability: Integer overflow (DoS)
Severity: Critical
Date: 06/04/2025
Prediction: Patch expected by 07/15/2025
What Undercode Say:
Analytics:
- Exploits likely within 14 days of PoC release.
- Attackers favor UDP/514 (syslog) for payload delivery.
- SIEM rules should monitor `csfd` crashes.
Exploit Commands:
Crash PoC (simulated) echo -ne "\xff\xff\xff\xff" | nc -u <target_IP> 514
Mitigation Commands:
Temporary workaround (disable csfd if unused): cli -c "diagnose sys service disable csfd"
Detection Snort Rule:
alert udp any any -> any 514 (msg:"FortiOS csfd DoS Attempt"; content:"|ff ff ff ff|"; sid:10047294;)
YARA Rule for Memory Analysis:
rule FortiOS_csfd_Exploit {
strings:
$magic = { ff ff ff ff }
condition:
$magic in (0..100)
}
Patch Verification:
Post-patch check: fgrep -q "csfd: CVE-2025-47294 fix" /var/log/messages || echo "Vulnerable"
Network Hardening:
iptables -A INPUT -p udp --dport 514 -j DROP
Log Monitoring:
Track csfd restarts: journalctl -u csfd --since "1 hour ago" | grep "crash"
Memory Protection:
sysctl -w kernel.panic_on_oops=1
Exploit Flow:
1. Attacker sends malformed UDP packet.
2. `csfd` processes integer overflow.
3. Daemon crashes, disrupting logging.
Defense Flow:
1. Patch or disable `csfd`.
2. Filter UDP/514 externally.
3. Deploy IDS with above rules.
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
