Firewall permits any-to-any outbound, defeating egress control
- Affected asset
- Perimeter firewall, internal to internet rule base
- Rating
- Moderate Possible 3 × Medium 3 = 9
Description
The firewall permits all outbound traffic from the internal network to the internet on any port. There is no egress filtering, so a compromised host can reach any command-and-control server and exfiltrate data over any protocol, and the permissive rule masks what legitimate traffic actually requires.
Evidence
# rule 900 (last in chain)
from LAN_ANY
to INTERNET_ANY
service ANY
action ALLOW
log disabled
# no restriction on destination, port, or protocol; no logging
A single any-to-any allow rule at the end of the chain, with logging off, permits and hides all outbound traffic.
Impact
Egress filtering is one of the most effective controls against data theft and malware command-and-control, and here it is absent. A compromised workstation can send data anywhere over any port with nothing to block or record it, which turns a contained incident into a breach and leaves no trail to investigate.
Remediation
Replace the any-to-any rule with an allow-list of the destinations and ports the business actually needs, default-deny the rest, and enable logging on the egress rules. Review outbound requirements per network segment, and alert on denied egress as an early sign of compromise.