ALMA-09-030380 - AlmaLinux OS 9 must disable mounting of udf.

Information

Removing support for unneeded filesystem types reduces the local attack surface of the server.

The UDF filesystem is used to write DVDs and so could assist in data exfiltration, the so-called "sneakernet".

Note that Microsoft Azure uses UDF.

Solution

To configure the system to prevent the udf kernel module from being loaded, create a *.conf file in /etc/modprobe.d/ with the following content:

install udf /bin/false
blacklist udf

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_CL_AlmaLinux_OS_9_V1R2_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-7a., CAT|II, CCI|CCI-000381, Rule-ID|SV-269348r1050230_rule, STIG-ID|ALMA-09-030380, Vuln-ID|V-269348

Plugin: Unix

Control ID: 2bb9c00896f2a3ea8f2f4937a64617bd2fce10790552a62c87dfdf22ba18b94c