CVE-2026-29127: IDC SFX2100 Privilege Escalation Flaw

CVE-2026-29127 Overview

The IDC SFX2100 Satellite Receiver contains an insecure permissions vulnerability in the monitor user's home directory configuration. The directory is set with permissions 0777, granting read, write, and execute access to all local users on the system. This misconfiguration may enable local privilege escalation when highly privileged processes and binaries reside within the affected directory.

Critical Impact

Local attackers with low-privilege access can potentially escalate to higher privileges by exploiting overly permissive file system permissions on directories containing privileged processes and binaries.

Affected Products

• IDC SFX2100 Satellite Receiver

Discovery Timeline

• 2026-03-05 - CVE-2026-29127 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-29127

Vulnerability Analysis

This vulnerability stems from improper privilege management (CWE-269) in the IDC SFX2100 Satellite Receiver firmware. The monitor user's home directory is configured with world-writable permissions (0777), which violates the principle of least privilege and creates a significant attack surface for local privilege escalation.

The vulnerability requires local access to exploit, meaning an attacker must first gain some level of access to the target system. Once local access is established, the overly permissive directory configuration allows any user to read, modify, or execute files within the monitor user's home directory. The presence of highly privileged processes and binaries in this directory significantly amplifies the risk, as attackers can potentially manipulate these files to achieve privilege escalation.

Root Cause

The root cause is an insecure default configuration where the monitor user's home directory permissions are set to 0777 instead of more restrictive permissions such as 0700 or 0750. This configuration flaw allows unauthorized users to access and modify sensitive files that should be protected.

Attack Vector

The attack vector is local, requiring the attacker to have authenticated access to the system with at least low-privilege credentials. An attacker could exploit this vulnerability by:

1. Gaining initial local access to the satellite receiver system
2. Identifying the monitor user's home directory with 0777 permissions
3. Locating privileged binaries or configuration files within the directory
4. Modifying or replacing these files with malicious versions
5. Waiting for or triggering execution of the privileged process to escalate privileges

The vulnerability allows for potential compromise of both confidentiality and integrity on the local system, with potential downstream effects on adjacent systems connected to the satellite receiver infrastructure.

Detection Methods for CVE-2026-29127

Indicators of Compromise

• Unexpected modifications to files within the monitor user's home directory
• New or modified executable files with timestamps inconsistent with normal system operations
• Anomalous process execution originating from the monitor user's home directory
• Unauthorized user access patterns targeting the /home/monitor directory path

Detection Strategies

• Implement file integrity monitoring (FIM) on the monitor user's home directory to detect unauthorized changes
• Audit and log all file access and modifications to directories with overly permissive settings
• Monitor for privilege escalation attempts using system auditing tools such as auditd
• Scan firmware configurations for directories with 0777 permissions during security assessments

Monitoring Recommendations

• Enable comprehensive logging of file system operations on the IDC SFX2100 device
• Configure alerts for any write operations to the monitor user's home directory by non-privileged users
• Regularly review system logs for suspicious activity patterns indicating privilege escalation attempts
• Implement network segmentation monitoring to detect lateral movement from compromised satellite receivers

How to Mitigate CVE-2026-29127

Immediate Actions Required

• Audit the IDC SFX2100 Satellite Receiver for directories with 0777 permissions
• Restrict permissions on the monitor user's home directory to 0700 or more appropriate values
• Review all files within the affected directory for signs of tampering or unauthorized modifications
• Limit local user access to the satellite receiver to only authorized personnel

Patch Information

At the time of publication, no vendor patch information is available. Organizations should monitor the Abdul MHS Blog Vulnerability Post for updates regarding this vulnerability and potential remediation guidance from the device manufacturer.

Workarounds

• Manually change directory permissions using chmod 700 /home/monitor or equivalent appropriate permissions
• Remove or relocate highly privileged binaries from the affected directory to a more secure location
• Implement additional access controls such as SELinux or AppArmor policies to restrict access to sensitive directories
• Consider network isolation of affected satellite receivers until proper remediation is available

# Configuration example - Remediate overly permissive directory permissions
# Identify the affected directory
ls -la /home/monitor

# Change permissions to restrict access to owner only
chmod 700 /home/monitor

# Verify the permission change
ls -la /home/ | grep monitor

# Audit for other world-writable directories on the system
find / -type d -perm -0777 -ls 2>/dev/null