| name | cis-apache-3.8 |
| description | Ensure the Lock File Is Secured |
| category | cis-apache |
| version | 3.6.0 |
| author | cyberstrike-official |
| tags | ["cis","apache","linux","privileges","permissions","ownership"] |
| cis_id | 3.8 |
| cis_benchmark | CIS Apache HTTP Server 2.2 Benchmark v3.6.0 |
| tech_stack | ["linux","apache"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
Ensure the Lock File Is Secured
Description
The LockFile directive sets the path to the lock file used when Apache uses fcntl(2) or flock(2) system calls to implement locking. Most Linux systems will default to using semaphores instead, so the directive may not apply. However, in the event a lock file is used, it is important for the lock file to be in a locally mounted directory that is not writable by other users.
Rationale
If the LockFile is placed in a writable directory, other accounts could create a denial of service attack and prevent the server from starting by creating a lock file with the same name.
Impact
None documented
Audit Procedure
Perform these steps to verify the lock file is secured properly:
- Find the directory in which the
LockFile would be created. The default value is the ServerRoot/logs directory.
- Verify that the lock file directory is not a directory within the Apache
DocumentRoot.
- Verify that the lock file directory is on a locally mounted hard drive rather than an NFS mounted file system.
- Verify that the ownership and group of the directory is
root:root (or the user under which apache initially starts up if not root).
- Verify that the permissions on the directory are only writable by root (or the startup user if not root).
Remediation
Perform these steps to properly secure the lock file:
- Find the directory in which the
LockFile would be created. The default value is the ServerRoot/logs directory.
- Modify the directory for the
LockFile so it is not within the Apache DocumentRoot and so it is on a locally mounted hard drive rather than an NFS mounted file system.
- Change the ownership and group of the directory to be
root:root.
- Change the permissions on the directory so it is only writable by root, or the user under which apache initially starts up (default is root).
Default Value
The default lock file is logs/accept.lock.
References
- https://httpd.apache.org/docs/2.2/mod/mpm_common.html#lockfile
CIS Controls
Version 6
18 Application Software Security
Application Software Security