Check: GEN003600
SUSE Linux Enterprise Server v11 for System z STIG:
GEN003600
(in versions v1 r12 through v1 r9)
Title
The system must not forward IPv4 source-routed packets. (Cat II impact)
Discussion
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router.
Check Content
Verify the system does not accept source-routed IPv4 packets. Procedure: # grep [01] /proc/sys/net/ipv4/conf/*/accept_source_route|egrep "default|all" If all of the returned lines do not end with 0, this is a finding. Note: The same setting is used by Linux for both the local acceptance and forwarding of source-routed IPv4 packets.
Fix Text
Configure the system to not accept source-routed IPv4 packets. Edit /etc/sysctl.conf and add a setting for "net.ipv4.conf.all.accept_source_route=0" and "net.ipv4.conf.default.accept_source_route=0". Reload the sysctls. Procedure: # sysctl -p
Additional Identifiers
Rule ID: SV-45719r1_rule
Vulnerability ID: V-12002
Group Title: GEN003600
Expert Comments
CCIs
| Number | Definition |
|---|---|
| CCI-001551 |
The organization defines approved authorizations for controlling the flow of information between interconnected systems. |
Controls
| Number | Title |
|---|---|
| AC-4 |
Information Flow Enforcement |