CVE-2026-29121: IDC SFX2100 Privilege Escalation Flaw

CVE-2026-29121 Overview

International Data Casting (IDC) SFX2100 satellite receiver ships with the /sbin/ip utility installed with the setuid bit set. This insecure default configuration grants elevated privileges to any local user who can execute the binary. A local attacker can leverage the GTFObins resource to perform privileged file reads as the root user on the local file system, potentially leading to other avenues for performing privileged actions and full system compromise.

Critical Impact

Local privilege escalation allowing any authenticated user to read arbitrary files as root and potentially execute other privileged operations on IDC SFX2100 satellite receivers.

Affected Products

• International Data Casting (IDC) SFX2100 Satellite Receiver

Discovery Timeline

• 2026-03-05 - CVE CVE-2026-29121 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-29121

Vulnerability Analysis

This vulnerability stems from CWE-269 (Improper Privilege Management), where the /sbin/ip binary on the IDC SFX2100 satellite receiver is configured with the setuid bit. When a binary has the setuid bit set, it executes with the permissions of its owner (root in this case) rather than the permissions of the user who runs it. This allows any local user with access to execute /sbin/ip to perform privileged operations that should be restricted to the root user.

The ip utility is a powerful networking tool that, when running with elevated privileges, can be abused through techniques documented on GTFObins to read arbitrary files from the file system with root permissions. This can lead to disclosure of sensitive information such as /etc/shadow, private keys, configuration files, and other protected data.

Root Cause

The root cause of this vulnerability is an insecure default configuration in the IDC SFX2100 firmware. The /sbin/ip binary has been installed with the setuid bit enabled, granting any local user the ability to execute this utility with root privileges. This represents a failure in the principle of least privilege, as the ip utility does not require setuid permissions for its intended network configuration purposes in a properly designed system.

Attack Vector

The attack requires local access to the IDC SFX2100 device. An attacker with valid credentials or shell access to the satellite receiver can execute the /sbin/ip binary to perform privileged file reads. The GTFObins project documents methods for abusing the ip command when it has setuid privileges, allowing attackers to read arbitrary files as root. This can be leveraged to obtain sensitive credentials, configuration data, or other protected information that could facilitate further attacks or complete system compromise.

For detailed exploitation techniques, refer to the GTFObins Command Reference and the Abdulmhs Blog Vulnerability Analysis.

Detection Methods for CVE-2026-29121

Indicators of Compromise

• Unexpected execution of /sbin/ip by non-administrative user accounts
• Access to sensitive files such as /etc/shadow, /etc/passwd, or SSH private keys by unauthorized users
• Audit logs showing unusual file read operations correlated with ip command execution
• Evidence of GTFObins techniques being used against the ip binary in command history

Detection Strategies

• Monitor process execution logs for /sbin/ip being run by non-root users
• Implement file integrity monitoring on sensitive system files that may be targeted for privileged reads
• Deploy endpoint detection solutions that can identify setuid binary abuse patterns
• Review system audit logs (auditd) for suspicious file access following ip command execution

Monitoring Recommendations

• Enable comprehensive logging of all command executions on IDC SFX2100 devices
• Configure alerts for access attempts to sensitive files like /etc/shadow or SSH keys
• Implement network segmentation to limit potential lateral movement from compromised satellite receivers
• Regularly audit setuid binaries on IoT and embedded devices in your environment

How to Mitigate CVE-2026-29121

Immediate Actions Required

• Remove the setuid bit from /sbin/ip using chmod u-s /sbin/ip if the setuid functionality is not required
• Restrict local access to IDC SFX2100 devices to only trusted administrators
• Audit all user accounts on affected devices and remove unnecessary accounts
• Implement network segmentation to isolate satellite receivers from sensitive network segments

Patch Information

No vendor patch information is currently available. Consult with International Data Casting (IDC) for official firmware updates that address this setuid misconfiguration. Until a patch is released, apply the recommended workarounds to reduce exposure.

Workarounds

• Remove the setuid bit from /sbin/ip with the command chmod u-s /sbin/ip
• Restrict shell access to the device by disabling unnecessary user accounts
• Implement strict access controls and require strong authentication for device access
• Monitor for signs of exploitation and implement compensating controls through network-level restrictions

# Remove setuid bit from /sbin/ip
chmod u-s /sbin/ip

# Verify the change was applied
ls -la /sbin/ip
# Should show permissions without 's': -rwxr-xr-x instead of -rwsr-xr-x