# Ensure noexec Mount Option is Set on /dev/shm Partition to Prevent Execution of Binaries

- Source: https://support.icompaas.com/support/solutions/articles/62000234969-ensure-noexec-mount-option-is-set-on-dev-shm-partition-to-prevent-execution-of-binaries
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [CIS Amazon Linux 2 Benchmark v3.0.0](https://support.icompaas.com/support/solutions/62000112696) › [CIS Amazon Linux 2 Benchmarks](https://support.icompaas.com/support/solutions/folders/62000169265)
- Last updated: 2026-05-29
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**Profile Applicability:** • Level 1

**Description:**  
 The noexec mount option prevents execution of binaries on the mounted filesystem. Applying this option to /dev/shm mitigates the risk of running unauthorized or malicious executables from shared memory.

**Rationale:** Setting the noexec option on /dev/shm reduces the chance that an attacker can execute malicious code from this temporary filesystem, enhancing system security.

**Impact:** Pros:

-   Helps prevent execution of unauthorized binaries or scripts in /dev/shm.  
    
-   Strengthens system defenses against execution-based attacks.  
    

Cons:

-   Some applications may require execution privileges in /dev/shm, which could be affected.  
    

**Default Value:** The noexec option is not usually set on /dev/shm by default and should be explicitly configured.

**Pre-requisites:**

-   Root or sudo privileges to modify /etc/fstab and remount filesystems.
    
-   /dev/shm must be mounted as a separate tmpfs partition.
    

**Remediation:**

### **Test Plan:**

**Using Linux command line:**

1.  Check current mount options for /dev/shm:  
    
     mount | grep /dev/shm
    
2.  Verify if noexec option is present in /etc/fstab for /dev/shm:
    
     grep /dev/shm /etc/fstab
    
      
    
    Expected output: Mount options for /dev/shm include noexec.
    

---

### **Implementation Plan:**

**Using Linux command line:**

1.  Edit /etc/fstab to add noexec to /dev/shm mount options. Example:  
    
    tmpfs  /dev/shm  tmpfs  defaults,nodev,nosuid,noexec  0  0
    
      
    
2.  Remount /dev/shm to apply new options without reboot:  
    
     mount -o remount,noexec /dev/shm
    
3.  Verify mount options:  
    
     mount | grep /dev/shm
    

---

### **Backout Plan:**

**Using Linux command line:**

1.  Remove noexec from /dev/shm mount options in /etc/fstab.  
    
2.  Remount /dev/shm without noexec:  
    
     mount -o remount /dev/shm
    
3.  Verify mount options:  
    
     mount | grep /dev/shm
    

---

**References:**

-   CIS Amazon Linux 2 Benchmark v3.0.0  
    
-   [NIST SP 800-53 Revision 5 - SC-7  
    ](https://csrc.nist.gov/publications/detail/sp/800-53/rev-5/final#sc-7)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.