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SLEM 5 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-261331SLEM-05-255030SV-261331r996459_ruleCCI-001133medium
Description
Terminating an unresponsive SSH session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle SSH session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, deallocating associated TCP/IP address/port pairs at the operating system level and deallocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean the operating system terminates all sessions or network access; it only ends the unresponsive session and releases the resources associated with that session.
STIGDate
SUSE Linux Enterprise Micro (SLEM) 5 Security Technical Implementation Guide2026-02-10

Related Frameworks

1 mapping across 4 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 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.

NET-07Network Connection Termination
1.00
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (24) 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-11Device Lock
1.00
AC-11(1)Pattern-hiding Displays
1.00
AC-12Session Termination
1.00
AC-12(2)Termination Message
1.00
AC-2(1)Automated System Account Management
1.00
AC-2(11)Usage Conditions
1.00
AC-2(2)Automated Temporary and Emergency Account Management
1.00
AC-2(3)Disable Accounts
1.00
AC-2(4)Automated Audit Actions
1.00
AC-7Unsuccessful Logon Attempts
1.00

+14 more (top 10 by confidence shown)

NIST 800-1710 mappings

No source states a mapping between these directly.

Also reachable in 3 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.

3.13.9
1.00
CCI1 mapping
CCI-001133
1.00

Details

Check Text (C-261331r996459_chk)

Verify the SSH server automatically terminates a user session after the SSH client has become unresponsive by using the following command: > sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*clientalivecountmax' /etc/ssh/sshd_config:ClientAliveCountMax 1 If "ClientAliveCountMax" is not set to "1", is commented out, missing, or conflicting results are returned, this is a finding.

Fix Text (F-64968r995859_fix)

Add or modify the following line in the "/etc/ssh/sshd_config" file: ClientAliveCountMax 1 Restart the SSH daemon for the changes to take effect: > sudo systemctl restart sshd.service