🛡️ Google GCE Network allows unrestricted POP3 traffic🟢
- Contextual name: 🛡️ GCE Network allows unrestricted POP3 traffic🟢
- ID:
/ce/ca/google/vpc/network-pop3-access - Tags:
- Policy Type:
COMPLIANCE_POLICY - Policy Categories:
SECURITY
Logic
Description
Description
This policy identifies Google GCE Networks that have Firewall Rules allowing unrestricted incoming traffic (
0.0.0.0/0) from the internet to the Post Office Protocol 3 (POP3) port,TCP/110.In GCP, Firewall Rules are defined at the VPC Network level. Each rule either allows or denies traffic based on its configuration. These configurations specify the type of traffic (e.g., protocols and ports) and the source or destination (e.g., IP addresses, subnets, and instances).
Rationale
POP3 is a legacy email retrieval protocol that transmits both authentication credentials (usernames and passwords) and email content in cleartext. Exposing a POP3 service to the public internet introduces a severe security risk, as attackers can intercept or manipulate unencrypted traffic. Such exposure may result in credential theft, unauthorized mailbox access, and data compromise. To ensure secure email communication, POP3 should be replaced with more secure alternatives such as IMAP over SSL/TLS (IMAPS) or other encrypted email access methods.
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Remediation
Remediation
From Google Cloud Console
- Go to
VPC Network.- Go to the
Firewall Rules.- Click the
Firewall Ruleto be modified.- Click
Edit.- Modify
Source IP rangesto specificIP.- Click
Save.From Google Cloud CLI
Identify Firewall Rules Allowing Public Access
gcloud compute networks get-effective-firewalls default \
--format="table(NAME, DIRECTION, IP_RANGES)" \
--filter="IP_RANGES:0.0.0.0/0 AND DIRECTION:INGRESS"Restrict the Source Range
Once you have identified the firewall rules, update each one to restrict access to trusted CIDR ranges:
gcloud compute firewall-rules update {{firewall-rule-name}} \
--source-ranges={{cidr-range1}},{{cidr-range2}}