CVE-2025-5473 is a high-severity integer overflow vulnerability affecting GIMP version 3.0.2, specifically in the parsing of ICO (icon) files. The root cause is improper validation of user-supplied data during ICO file processing, which leads to an integer overflow or wraparound condition before memory is written. This flaw allows an attacker to manipulate the parsing logic such that the integer overflow causes memory corruption, enabling remote code execution (RCE) within the context of the GIMP process. Exploitation requires user interaction, meaning the victim must either open a maliciously crafted ICO file or visit a webpage that triggers the vulnerability through embedded content. The vulnerability is classified under CWE-190 (Integer Overflow or Wraparound), a common weakness that can lead to buffer overflows or other memory corruption issues. The CVSS v3.0 base score is 7.8, indicating high severity, with attack vector local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits are currently reported in the wild, and no official patches have been linked yet. This vulnerability was identified and assigned by the Zero Day Initiative (ZDI) as ZDI-CAN-26752. Given GIMP's widespread use as an open-source image manipulation tool, the vulnerability poses a significant risk if exploited, especially in environments where users frequently handle ICO files or receive such files from untrusted sources.

For European organizations, the impact of CVE-2025-5473 can be substantial. GIMP is popular among graphic designers, digital artists, and IT professionals, including in sectors such as media, advertising, education, and software development. Successful exploitation could allow attackers to execute arbitrary code, potentially leading to full system compromise, data theft, or deployment of malware such as ransomware. The requirement for user interaction reduces the risk somewhat but does not eliminate it, as phishing campaigns or malicious websites could easily trick users into opening crafted ICO files or visiting harmful pages. Confidentiality, integrity, and availability of affected systems are all at high risk. Organizations relying on GIMP for image processing or creative workflows may face operational disruptions and data breaches. Additionally, compromised systems could be leveraged as footholds for lateral movement within corporate networks. The lack of a patch at the time of disclosure increases exposure, emphasizing the need for immediate mitigation. The threat is particularly relevant for organizations with less mature endpoint security or those that do not restrict file types or monitor user downloads effectively.

1. Immediate mitigation should include restricting the opening of ICO files from untrusted or unknown sources within GIMP. 2. Educate users about the risks of opening files from unverified origins and visiting suspicious websites, emphasizing the need for caution with ICO files. 3. Employ endpoint security solutions capable of detecting and blocking exploitation attempts targeting this vulnerability, including heuristic and behavior-based detection for anomalous GIMP process activity. 4. Use application whitelisting or sandboxing techniques to limit the impact of potential exploitation by isolating GIMP processes. 5. Monitor network traffic and system logs for unusual activity that could indicate exploitation attempts. 6. Regularly check for and apply official patches or updates from the GIMP project as soon as they become available. 7. Consider temporarily disabling or limiting GIMP usage in high-risk environments until a patch is released. 8. Implement file type filtering at email gateways and web proxies to block or quarantine ICO files from external sources. These steps go beyond generic advice by focusing on user behavior, file handling policies, and layered security controls tailored to the nature of this vulnerability.