CVE-2024-25082 Overview
CVE-2024-25082 is a command injection vulnerability in FontForge's splinefont component through version 20230101. The flaw allows attackers to execute arbitrary shell commands by supplying crafted archive or compressed font files. FontForge shells out to external decompression utilities when opening supported font packages, and unsanitized file names are passed into these commands. The issue is tracked under CWE-77: Improper Neutralization of Special Elements used in a Command. Affected distributions include upstream FontForge, Debian Linux, and Fedora.
Critical Impact
A user opening a maliciously named font archive in FontForge can trigger arbitrary command execution in their session, enabling data theft or foothold establishment on the workstation.
Affected Products
- FontForge through 20230101
- Debian Linux (fixed via Debian LTS advisory)
- Fedora 40 (fixed via Fedora package update)
Discovery Timeline
- 2024-02-26 - CVE-2024-25082 published to NVD
- 2024-03-08 - Openwall OSS Security advisory released
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-25082
Vulnerability Analysis
FontForge supports opening fonts stored inside archives and compressed containers such as .tar, .gz, .bz2, .zip, and .Z. When a user opens one of these files, splinefont invokes external command-line utilities to extract the contents. The file path or embedded member name is concatenated into the shell command without proper neutralization of shell metacharacters. An attacker who controls the file name can inject arbitrary commands that execute with the privileges of the user running FontForge.
Because interaction is limited to opening a font file, the attack aligns with common social engineering delivery methods, including malicious downloads and email attachments targeting font designers.
Root Cause
The root cause is improper neutralization of special elements in command construction inside FontForge's archive and compression handling routines. Rather than executing decompression utilities with argument arrays and validated paths, splinefont builds shell command strings using untrusted filename input, allowing metacharacters such as backticks, $(), and ; to break out of the intended command context.
Attack Vector
An attacker crafts a font archive whose filename contains shell metacharacters and injected commands. The attacker delivers the file through email, a download link, or a font-sharing platform. When a victim opens the file in FontForge, splinefont invokes a shell to decompress the archive and evaluates the injected payload. See the GitHub FontForge Pull Request for the code paths involved.
No verified proof-of-concept code is published in the referenced advisories. Technical exploitation details are described in the Openwall OSS Security Update.
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Stop Exploit AttemptsDetection Methods for CVE-2024-25082
Indicators of Compromise
- Font archive files with unusual names containing shell metacharacters such as backticks, $(), semicolons, or pipes.
- Unexpected child processes such as sh, bash, curl, or wget spawned by the fontforge process.
- Outbound network connections initiated by FontForge or its helper processes shortly after a font file is opened.
Detection Strategies
- Monitor process ancestry for fontforge or splinefont spawning shells or scripting interpreters.
- Alert on file writes to autostart locations, cron directories, or SSH configuration files by user sessions that recently launched FontForge.
- Inspect downloaded font archives for filenames that deviate from expected character sets before opening.
Monitoring Recommendations
- Enable process telemetry on workstations used by font designers and publishing teams.
- Log command-line arguments passed to decompression utilities to identify injected payloads.
- Correlate FontForge execution events with outbound connections and new persistence artifacts.
How to Mitigate CVE-2024-25082
Immediate Actions Required
- Upgrade FontForge to a version released after 20230101 that includes the fix from pull request #5367.
- Apply the Debian LTS update described in the Debian LTS Announcement.
- Apply the Fedora update described in the Fedora Package Announcement.
- Instruct users to only open font archives obtained from trusted sources.
Patch Information
Upstream FontForge addressed the issue in the pull request tracked at GitHub FontForge Pull Request #5367. Distribution-specific packages are available from the FontForge Downloads Page, Debian LTS repositories, and Fedora update channels. Administrators should ensure package managers pull the fixed builds before allowing font design workflows to resume on unpatched hosts.
Workarounds
- Avoid opening compressed or archived font files directly in FontForge; decompress them manually with vetted tools first.
- Rename downloaded archives to a safe character set before opening in FontForge.
- Run FontForge inside a sandbox or dedicated low-privilege user account to contain potential command execution.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
