OpenControls Logo

STIG Viewer

STIGViewer Support

Ubuntu OS must be configured to use TCP syncookies.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-275616RIIM-OS-253010SV-275616r1147898_ruleCCI-001095medium
Description
Denial of service (DoS) is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning.
STIGDate
Riverbed NetIM OS Security Technical Implementation Guide2025-10-02

Related Frameworks

1 mapping across 4 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (2) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

CAP-02Resource Priority
0.50
CAP-03Capacity Planning
0.50
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (13) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-17(10)Authenticate Remote Commands
1.00
AC-17(9)Disconnect or Disable Access
1.00
AC-3Access Enforcement
1.00
AC-4Information Flow Enforcement
1.00
AU-3Content of Audit Records
1.00
CM-6Configuration Settings
1.00
CM-7Least Functionality
1.00
CM-7(2)Prevent Program Execution
1.00
SC-47Alternate Communications Paths
1.00
SC-5Denial-of-service Protection
1.00

+3 more (top 10 by confidence shown)

CCI1 mapping
CCI-001095
1.00
NIST CSF 2.00 mappings

No source states a mapping between these directly.

Also reachable in 4 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

PR.IR-04
0.50

Details

Check Text (C-275616r1147898_chk)

Verify Ubuntu OS is configured to use TCP syncookies by using the following command: $ sysctl net.ipv4.tcp_syncookies net.ipv4.tcp_syncookies = 1 If the value is not "1", this is a finding. Check the saved value of TCP syncookies by using the following command: $ sudo grep -ir net.ipv4.tcp_syncookies /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf 2> /dev/null If the "net.ipv4.tcp_syncookies" option is not set to "1", is commented out, or is missing, this is a finding. If conflicting results are returned, this is a finding.

Fix Text (F-79623r1147897_fix)

Configure Ubuntu OS to use TCP syncookies by using the following command: $ sudo sysctl -w net.ipv4.tcp_syncookies=1 If "1" is not the system's default value, add or update the following line in "/etc/sysctl.conf": net.ipv4.tcp_syncookies = 1