Guide to the Secure Configuration of Debian 11
Rules, Groups, and Values defined within the XCCDF Benchmark
-
The percentage remaining in disk space before prompting space_left_action
The setting for space_left as a percentage in /etc/audit/auditd.confValue -
Configure auditd to use audispd's syslog plugin
To configure the <code>auditd</code> service to use the <code>syslog</code> plug-in of the <code>audispd</code> audit event multiplexor, set the <c...Rule Medium Severity -
Write Audit Logs to the Disk
To configure Audit daemon to write Audit logs to the disk, set <code>write_logs</code> to <code>yes</code> in <code>/etc/audit/auditd.conf</code>. ...Rule Medium Severity -
Configure auditd Disk Error Action on Disk Error
The <code>auditd</code> service can be configured to take an action when there is a disk error. Edit the file <code>/etc/audit/auditd.conf</code>. ...Rule Medium Severity -
Configure auditd Disk Error Action on Disk Error
The <code>auditd</code> service can be configured to take an action when there is a disk error. Edit the file <code>/etc/audit/auditd.conf</code>. ...Rule Medium Severity -
Configure auditd Disk Full Action when Disk Space Is Full
The <code>auditd</code> service can be configured to take an action when disk space is running low but prior to running out of space completely. Ed...Rule Medium Severity -
Configure auditd Disk Full Action when Disk Space Is Full
The <code>auditd</code> service can be configured to take an action when disk space is running low but prior to running out of space completely. Ed...Rule Medium Severity -
Configure auditd mail_acct Action on Low Disk Space
The <code>auditd</code> service can be configured to send email to a designated account in certain situations. Add or correct the following line in...Rule Medium Severity -
Configure auditd admin_space_left Action on Low Disk Space
The <code>auditd</code> service can be configured to take an action when disk space is running low but prior to running out of space completely. Ed...Rule Medium Severity -
Configure auditd Max Log File Size
Determine the amount of audit data (in megabytes) which should be retained in each log file. Edit the file <code>/etc/audit/auditd.conf</code>. Add...Rule Medium Severity -
System Accounting with auditd
The <code>auditd</code> program can perform comprehensive monitoring of system activity. This section makes use of recommended configuration settin...Group -
Configure auditd max_log_file_action Upon Reaching Maximum Log Size
The default action to take when the logs reach their maximum size is to rotate the log files, discarding the oldest one. To configure the action ta...Rule Medium Severity -
Configure auditd max_log_file_action Upon Reaching Maximum Log Size
The default action to take when the logs reach their maximum size is to rotate the log files, discarding the oldest one. To configure the action ta...Rule Medium Severity -
Configure auditd Number of Logs Retained
Determine how many log files <code>auditd</code> should retain when it rotates logs. Edit the file <code>/etc/audit/auditd.conf</code>. Add or modi...Rule Medium Severity -
Configure auditd space_left Action on Low Disk Space
The <code>auditd</code> service can be configured to take an action when disk space <i>starts</i> to run low. Edit the file <code>/etc/audit/auditd...Rule Medium Severity -
Set number of records to cause an explicit flush to audit logs
To configure Audit daemon to issue an explicit flush to disk command after writing <xccdf-1.2:sub idref="xccdf_org.ssgproject.content_value_var_aud...Rule Medium Severity -
Include Local Events in Audit Logs
To configure Audit daemon to include local events in Audit logs, set <code>local_events</code> to <code>yes</code> in <code>/etc/audit/auditd.conf<...Rule Medium Severity -
Resolve information before writing to audit logs
To configure Audit daemon to resolve all uid, gid, syscall, architecture, and socket address information before writing the events to disk, set <co...Rule Low Severity -
Appropriate Action Must be Setup When the Internal Audit Event Queue is Full
The audit system should have an action setup in the event the internal event queue becomes full. To setup an overflow action edit <code>/etc/audit/...Rule Medium Severity -
AppArmor
Many security vulnerabilities result from bugs in trusted programs. A trusted program runs with privileges that attackers want to possess. The prog...Group -
AppArmor profiles mode
enforce - Set all AppArmor profiles to enforce mode
complain - Set all AppArmor profiles to complain modeValue -
GRUB2 bootloader configuration
During the boot process, the boot loader is responsible for starting the execution of the kernel and passing options to it. The boot loader allows ...Group -
L1TF vulnerability mitigation
Defines the L1TF vulneratility mitigations to employ.Value -
MDS vulnerability mitigation
Defines the MDS vulneratility mitigation to employ.Value -
Confidence level on Hardware Random Number Generator
Defines the level of trust on the hardware random number generators available in the system and the percentage of entropy to credit.Value -
Spec Store Bypass Mitigation
This controls how the Speculative Store Bypass (SSB) vulnerability is mitigated.Value -
Disable Recovery Booting
Debian 11 systems support an "recovery boot" option that can be used to prevent services from being started. The <code>GRUB_DISABLE_RECOVERY</code>...Rule Medium Severity -
IOMMU configuration directive
On x86 architecture supporting VT-d, the IOMMU manages the access control policy between the hardware devices and some of the system critical u...Rule Unknown Severity -
Configure L1 Terminal Fault mitigations
L1 Terminal Fault (L1TF) is a hardware vulnerability which allows unprivileged speculative access to data which is available in the Level 1 Data Ca...Rule High Severity -
Force kernel panic on uncorrected MCEs
A Machine Check Exception is an error generated by the CPU itdetects an error in itself, memory or I/O devices. These errors may be corrected and g...Rule Medium Severity -
Ensure SMAP is not disabled during boot
The SMAP is used to prevent the supervisor mode from unintentionally reading/writing into memory pages in the user space, it is enabled by default ...Rule Medium Severity -
Ensure SMEP is not disabled during boot
The SMEP is used to prevent the supervisor mode from executing user space code, it is enabled by default since Linux kernel 3.0. But it could be di...Rule Medium Severity -
Configure the confidence in TPM for entropy
The TPM security chip that is available in most modern systems has a hardware RNG. It is also used to feed the entropy pool, but generally not cred...Rule Low Severity -
Disable merging of slabs with similar size
The kernel may merge similar slabs together to reduce overhead and increase cache hotness of objects. Disabling merging of slabs keeps the slabs se...Rule Medium Severity -
Configure Speculative Store Bypass Mitigation
Certain CPUs are vulnerable to an exploit against a common wide industry wide performance optimization known as Speculative Store Bypass (SSB). In...Rule Medium Severity -
Enforce Spectre v2 mitigation
Spectre V2 is an indirect branch poisoning attack that can lead to data leakage. An exploit for Spectre V2 tricks the indirect branch predictor int...Rule High Severity -
Ensure debug-shell service is not enabled during boot
systemd's <code>debug-shell</code> service is intended to diagnose systemd related boot issues with various <code>systemctl</code> commands. Once e...Rule Medium Severity -
Non-UEFI GRUB2 bootloader configuration
Non-UEFI GRUB2 bootloader configurationGroup -
UEFI GRUB2 bootloader configuration
UEFI GRUB2 bootloader configurationGroup -
zIPL bootloader configuration
During the boot process, the bootloader is responsible for starting the execution of the kernel and passing options to it. The default Debian 11 bo...Group -
Protect Random-Number Entropy Pool
The I/O operations of the Linux kernel block layer due to their inherently unpredictable execution times have been traditionally considered as a re...Group -
Ensure Solid State Drives Do Not Contribute To Random-Number Entropy Pool
For each solid-state drive on the system, run:# echo 0 > /sys/block/DRIVE/queue/add_random
Rule Medium Severity -
Kernel Configuration
Contains rules that check the kernel configuration that was used to build it.Group -
Hash function for kernel module signing
The hash function to use when signing modules during kernel build process.Value -
Key and certificate for kernel module signing
The private key and certificate to use when signing modules during kernel build process. On systems where the OpenSSL ENGINE_pkcs11 is functional —...Value -
Kernel panic timeout
The time, in seconds, to wait until a reboot occurs. If the value is <code>0</code> the system never reboots. If the value is less than <code>0</co...Value -
Do not allow ACPI methods to be inserted/replaced at run time
This debug facility allows ACPI AML methods to be inserted and/or replaced without rebooting the system. This configuration is available from kerne...Rule Low Severity -
Disable kernel support for MISC binaries
Enabling <code>CONFIG_BINFMT_MISC</code> makes it possible to plug wrapper-driven binary formats into the kernel. This is specially useful for prog...Rule Medium Severity -
Enable support for BUG()
Disabling this option eliminates support for BUG and WARN, reducing the size of your kernel image and potentially quietly ignoring numerous fatal c...Rule Medium Severity -
Disable compatibility with brk()
Enabling compatiliby with <code>brk()</code> allows legacy binaries to run (i.e. those linked against libc5). But this compatibility comes at the c...Rule Medium Severity
Node 2
The content of the drawer really is up to you. It could have form fields, definition lists, text lists, labels, charts, progress bars, etc. Spacing recommendation is 24px margins. You can put tabs in here, and can also make the drawer scrollable.