CVE-2026-58459 - gpsd gpsprof Command Injection

gpsd, an open-source service daemon for GPS receivers, through release 3.27.5, contains a critical command injection vulnerability, CVE-2026-58459, within its gpsprof utility. This flaw allows an attacker to achieve arbitrary shell command execution on systems that process potentially untrusted GPS device subtype values. The vulnerability arises when the gpsprof utility generates gnuplot programs for data visualization. Specifically, if a maliciously crafted GPS device subtype value, sourced from a DEVICES JSON log entry or an NMEA PGRMT sentence, contains backtick payloads, gpsprof will embed these unescaped payloads directly into the set title statement of the gnuplot script. When a victim subsequently renders this generated plot using the gnuplot program, the embedded shell commands are executed with the privileges of the user running gnuplot. This impacts systems that use gpsprof to analyze GPS data, potentially leading to full system compromise or data exfiltration by exploiting an often overlooked data processing workflow.

Attack Chain

1. An attacker crafts a malicious GPS device subtype value containing shell command payloads (e.g., test`id\). This value can be embedded in a DEVICES JSON log entry or an NMEA PGRMT sentence.
2. The malicious GPS data is provided to a system running gpsd.
3. The gpsprof utility is invoked on the system to process the GPS data and generate a gnuplot program.
4. gpsprof reads the malicious device subtype value and, due to improper escaping, embeds the backtick payload directly into a set title statement within the generated gnuplot script.
5. A legitimate user or automated process attempts to render the generated plot by executing the crafted gnuplot program using the gnuplot application.
6. Upon execution, the gnuplot application interprets the backtick payload within the set title command, leading to the execution of the attacker's arbitrary shell commands with the privileges of the user running gnuplot.
7. The attacker's commands execute, potentially leading to system compromise, data exfiltration, or further lateral movement.

Impact

Successful exploitation of CVE-2026-58459 grants an attacker arbitrary shell command execution as the user running the gpsprof and gnuplot workflow. This can lead to complete compromise of the affected system, allowing for data exfiltration, installation of additional malware, or further lateral movement within the network. While no specific victim count or targeted sectors have been disclosed, any organization or individual processing potentially untrusted GPS data using gpsd versions through 3.27.5 is at risk. The ease of exploitation by simply controlling an input value makes this a significant threat.

Recommendation

• Patch CVE-2026-58459 immediately by upgrading gpsd to a version beyond 3.27.5, or applying commit 4c06658.
• Deploy the Sigma rule "Detects CVE-2026-58459 Exploitation - gnuplot Spawning Suspicious Processes" in this brief to your SIEM to detect suspicious process execution originating from gnuplot on Linux and macOS systems.
• Enable process_creation logging for Linux and macOS endpoints to ensure telemetry is available for the provided detection rule.
• Review and restrict execution of gpsprof and gnuplot to trusted data sources and environments where untrusted input cannot be processed.