CVE-2024-41637: RaspAP Privilege Escalation Vulnerability

CVE-2024-41637 Overview

CVE-2024-41637 is a privilege escalation vulnerability in RaspAP versions prior to 3.1.5. RaspAP is an open-source wireless access point and router software primarily deployed on Raspberry Pi devices. The vulnerability allows the www-data user, which runs the web server, to escalate to root privileges. The www-data account has write access to the restapi.service systemd unit file and holds passwordless Sudo privileges for several critical commands. An attacker who compromises the web application can leverage these misconfigurations to execute arbitrary commands as root. The flaw is categorized under [CWE-77] (Improper Neutralization of Special Elements used in a Command).

Critical Impact

An attacker with access to the www-data context can escalate to root by modifying the restapi.service file or invoking passwordless Sudo commands, leading to full system compromise.

Affected Products

• RaspAP versions prior to 3.1.5
• RaspAP Web GUI (raspap-webgui)
• Raspberry Pi systems running vulnerable RaspAP installations

Discovery Timeline

• 2024-07-29 - CVE-2024-41637 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2024-41637

Vulnerability Analysis

The vulnerability stems from insecure file permissions and an overly permissive Sudo configuration in RaspAP. The web server runs as the www-data user, which is granted write access to the restapi.service systemd unit file. An attacker who controls the web context can modify this service definition to execute arbitrary commands when the service starts or restarts. Because systemd services typically run as root, this enables direct privilege escalation. Compounding the issue, the www-data user is configured with passwordless Sudo privileges for several critical commands. This allows the same attacker to invoke privileged operations without authentication. The combination of writable service files and unrestricted Sudo rights creates a reliable path from low-privileged web access to full root control.

Root Cause

The root cause is a configuration weakness in RaspAP installations prior to 3.1.5. The installer assigns inappropriate filesystem permissions to restapi.service and provisions Sudo rules that permit www-data to run sensitive commands without a password. These defaults violate the principle of least privilege.

Attack Vector

An attacker first requires access to the www-data execution context, typically through an authenticated web session or a chained web vulnerability. Once in that context, the attacker rewrites restapi.service to launch an attacker-controlled binary, or invokes one of the passwordless Sudo commands to read, write, or execute privileged operations. Technical analysis of the issue is available in the 0xZon Blog CVE-2024-41637 Analysis and the GitHub RaspAP Web GUI Repository.

Detection Methods for CVE-2024-41637

Indicators of Compromise

• Unauthorized modifications to /lib/systemd/system/restapi.service or related unit files
• Unexpected systemctl daemon-reload or systemctl restart restapi invocations from the web server context
• Sudo log entries showing www-data executing privileged commands without password prompts
• New or modified setuid binaries, cron jobs, or SSH keys following web activity

Detection Strategies

• Monitor file integrity on systemd unit files, especially restapi.service, and alert on writes by non-root users
• Audit /etc/sudoers and /etc/sudoers.d/ for entries granting NOPASSWD rights to www-data
• Correlate web access logs with subsequent Sudo or systemd activity to identify exploitation chains
• Inspect RaspAP installations and confirm the running version is 3.1.5 or later

Monitoring Recommendations

• Enable Linux audit rules (auditd) on systemd unit directories and the Sudo binary
• Forward /var/log/auth.log and journald entries to a central log platform for analysis
• Alert on process executions where the parent is the RaspAP web service and the child runs as root

How to Mitigate CVE-2024-41637

Immediate Actions Required

• Upgrade RaspAP to version 3.1.5 or later on all affected devices
• Restrict write permissions on restapi.service so only root can modify the file
• Review and remove any NOPASSWD Sudo entries assigned to www-data that are not strictly required
• Rotate credentials and inspect affected systems for signs of prior exploitation

Patch Information

RaspAP version 3.1.5 addresses the vulnerability by correcting file permissions and tightening the Sudo configuration. Patch details are available in the GitHub RaspAP Web GUI Repository.

Workarounds

• Set ownership of restapi.service to root:root with mode 0644 until patching is possible
• Remove passwordless Sudo entries for www-data and require explicit authentication for administrative commands
• Restrict network exposure of the RaspAP management interface to trusted hosts using firewall rules

# Configuration example
sudo chown root:root /lib/systemd/system/restapi.service
sudo chmod 0644 /lib/systemd/system/restapi.service
sudo systemctl daemon-reload

# Review sudoers for www-data entries
sudo grep -R "www-data" /etc/sudoers /etc/sudoers.d/