CVE-2025-2761: GIMP FLI File Parsing RCE Vulnerability

CVE-2025-2761 Overview

CVE-2025-2761 is an out-of-bounds write vulnerability in the GIMP image editing application that allows remote attackers to execute arbitrary code on affected installations. The vulnerability exists within the parsing of FLI (Autodesk Animator) files and stems from improper validation of user-supplied data, which can result in a write operation past the end of an allocated buffer.

User interaction is required to exploit this vulnerability—the target must open a malicious FLI file or visit a malicious page that delivers such a file. Upon successful exploitation, an attacker can execute arbitrary code in the context of the current process, potentially leading to complete system compromise depending on the privileges of the user running GIMP.

Critical Impact

Remote code execution through malicious FLI file parsing enables attackers to gain control of the victim's system with the privileges of the GIMP process.

Affected Products

• GIMP version 2.10.38
• Earlier versions of GIMP with FLI file parsing support may also be affected

Discovery Timeline

• 2025-04-23 - CVE-2025-2761 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-2761

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-Bounds Write), a memory corruption flaw that occurs when the application writes data beyond the boundaries of an allocated memory buffer. In the context of GIMP's FLI file parser, the vulnerability manifests when processing specially crafted FLI animation files.

FLI files are a legacy animation format originally developed by Autodesk for their Animator software. The format uses various chunk types to describe animation frames and color data. GIMP includes support for importing these files, but the parsing implementation fails to properly validate certain fields within the file structure before using them in memory operations.

The lack of proper bounds checking allows an attacker to craft a malicious FLI file that, when parsed, causes GIMP to write data beyond the allocated buffer boundaries. This memory corruption can be leveraged to overwrite critical data structures, function pointers, or return addresses, ultimately enabling arbitrary code execution.

Root Cause

The root cause of this vulnerability is insufficient input validation in GIMP's FLI file parsing code. Specifically, the parser does not adequately verify that user-supplied data from the FLI file conforms to expected boundaries before using it to calculate buffer sizes or write positions. This allows malformed dimension values, chunk sizes, or frame data within a malicious FLI file to trigger writes outside the bounds of allocated buffers.

Attack Vector

The attack requires user interaction through a local attack vector. An attacker must convince a victim to open a maliciously crafted FLI file in GIMP. This can be accomplished through various social engineering techniques:

• Sending the malicious file via email as an attachment
• Hosting the file on a compromised or attacker-controlled website
• Distributing the file through file-sharing platforms or archives
• Embedding the file in documents or archives that appear legitimate

Once the victim opens the malicious FLI file in GIMP, the parsing vulnerability is triggered, and arbitrary code execution occurs in the context of the GIMP process. The attacker gains the same privileges as the user running GIMP, which could include access to sensitive files, the ability to install malware, or further lateral movement within the network.

For complete technical details regarding the exploitation mechanism, refer to the Zero Day Initiative Advisory ZDI-25-204.

Detection Methods for CVE-2025-2761

Indicators of Compromise

• Presence of unusual or unexpected FLI files in download directories, email attachments, or temporary folders
• GIMP process crashes or unexpected behavior when opening image files
• Suspicious child processes spawned from the GIMP process (gimp or gimp-2.10)
• Memory access violations or segmentation faults logged in system logs related to GIMP

Detection Strategies

• Monitor for GIMP process executing suspicious child processes or making unusual system calls
• Implement file type validation that inspects FLI file headers and structure for anomalies before allowing user access
• Deploy endpoint detection solutions that can identify memory corruption exploitation attempts
• Use application sandboxing to contain potential exploitation of image processing applications

Monitoring Recommendations

• Enable detailed logging for image editing applications and monitor for crash events
• Implement network monitoring to detect downloads of FLI files from suspicious sources
• Monitor user directories for newly created executable files following GIMP file operations
• Configure SentinelOne to alert on behavioral indicators of memory corruption exploitation

How to Mitigate CVE-2025-2761

Immediate Actions Required

• Update GIMP to the latest patched version as soon as vendor updates are available
• Avoid opening FLI files from untrusted or unknown sources
• Configure email filters to block or quarantine FLI file attachments
• Consider temporarily disabling FLI file import functionality if operationally feasible
• Run GIMP with reduced privileges or in a sandboxed environment

Patch Information

Organizations should monitor official GIMP release channels and security advisories for patched versions. The Debian LTS Announcement provides distribution-specific patch information for Debian-based systems. Additionally, the Zero Day Initiative Advisory ZDI-25-204 contains details regarding the coordinated disclosure.

Workarounds

• Remove or rename the FLI file import plugin from the GIMP plugins directory to prevent parsing of malicious files
• Use alternative image viewers that do not support FLI format for untrusted files
• Implement application whitelisting to prevent unauthorized code execution from GIMP's process context
• Deploy network-based file inspection to detect and block potentially malicious FLI files before they reach endpoints

# Example: Disable FLI plugin on Linux (adjust path for your installation)
# Locate and rename the FLI plugin to prevent loading
find /usr/lib/gimp -name "*fli*" -type f -exec mv {} {}.disabled \;

# Verify GIMP installation and version
gimp --version