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How the CVE Works:
The vulnerability exists in GoBGP’s FlowSpec parser (pkg/packet/bgp/bgp.go). When processing FlowSpec rules, the parser fails to validate the minimum length of incoming packets. An attacker can exploit this by sending a crafted BGP packet containing fewer than 20 bytes, triggering a buffer underflow or improper memory access. This leads to a segmentation fault, crashing the GoBGP daemon and causing a denial of service. The issue stems from insufficient boundary checks during packet parsing, allowing malformed inputs to disrupt service availability.
DailyCVE Form:
Platform: GoBGP
Version: < 3.35.0
Vulnerability: FlowSpec parser crash
Severity: Moderate
Date: Apr 21, 2025
What Undercode Say:
Exploitation:
- Craft a malformed BGP packet with <20 bytes targeting FlowSpec.
- Send the packet to a vulnerable GoBGP instance:
echo -ne '\x01\x02\x03\x04' | nc <target_IP> 179
- Observe daemon crash (check logs for segmentation faults).
Mitigation:
1. Upgrade to GoBGP ≥ 3.35.0.
2. Implement BGP message length validation:
if len(packet) < 20 {
return errors.New("invalid packet length")
}
3. Use network ACLs to restrict BGP peers:
iptables -A INPUT -p tcp --dport 179 -s <trusted_IP> -j ACCEPT
Detection:
1. Monitor logs for repeated crashes:
journalctl -u gobgpd | grep "panic"
2. Capture suspicious BGP packets:
tcpdump -i eth0 'port 179 and (less 20)' -w gobgp_debug.pcap
Analytics:
- Attack Vector: Network-adjacent
- Complexity: Low (no auth required)
- Impact: Availability (DoS)
- CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
References:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
