cyberstrikeus 1.5.1 Ensure core dumps are restricted (Scored)
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
A core dump is the memory of an executable program. It is generally used to determine why a program aborted. It can also be used to glean confidential information from a core file. The system provides the ability to set a soft limit for core dumps, but this can be overridden by the user.
Rationale
Setting a hard limit on core dumps prevents users from overriding the soft variable. If core dumps are required, consider setting limits for user groups (see limits.conf(5)). In addition, setting the fs.suid_dumpable variable to 0 will prevent setuid programs from dumping core.
Audit Procedure
Run the following commands and verify output matches:
grep "hard core" /etc/security/limits.conf /etc/security/limits.d/*
# Expected: * hard core 0
sysctl fs.suid_dumpable
# Expected: fs.suid_dumpable = 0
grep "fs\.suid_dumpable" /etc/sysctl.conf /etc/sysctl.d/*
# Expected: fs.suid_dumpable = 0
Expected Result
* hard core 0
fs.suid_dumpable = 0
fs.suid_dumpable = 0
Remediation
Add the following line to /etc/security/limits.conf or a /etc/security/limits.d/* file:
* hard core 0
Set the following parameter in /etc/sysctl.conf or a /etc/sysctl.d/* file:
fs.suid_dumpable = 0
Run the following command to set the active kernel parameter:
sysctl -w fs.suid_dumpable=0
Default Value
Not applicable.
Notes
It has been reported that due to Ubuntu bug #50093 this setting (and some others) can fail to apply properly on reboot requiring it to be manually re-applied. One method of accomplishing this is to add sysctl -p to run on reboot to your systems crontab.
References
- CIS Controls: 13 Data Protection
Profile
- Level 1 - Server
- Level 1 - Workstation