CVE-2002-0898 in Web Browser
Summary
by MITRE
Opera 6.0.1 and 6.0.2 allows a remote web site to upload arbitrary files from the client system, without prompting the client, via an input type=file tag whose value contains a newline.
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Analysis
by VulDB Data Team • 07/04/2025
This vulnerability exists in Opera web browsers version 6.0.1 and 6.0.2 where the file upload functionality fails to properly validate file paths submitted through html input type=file elements. The flaw specifically occurs when a malicious website constructs a file input field with a value containing newline characters, allowing the browser to interpret this input as a command to upload files from arbitrary locations on the client system without any user confirmation or prompt. The vulnerability stems from insufficient sanitization of file path inputs, enabling attackers to bypass normal file upload restrictions and potentially access sensitive files from the victim's system.
The technical implementation of this vulnerability exploits the way Opera handles file input validation by not properly stripping or escaping newline characters from file path values before processing. When a web page with malicious javascript or html code loads, it can construct a file input field with a value that includes newline sequences which cause the browser to interpret the file path differently than intended. This behavior creates an opportunity for arbitrary file upload attacks where the attacker can specify any file path on the client system, potentially leading to unauthorized access to sensitive data, system files, or personal documents stored locally on the user's machine.
The operational impact of this vulnerability is significant as it allows remote attackers to perform unauthorized file operations on client systems without user interaction or awareness. An attacker could craft a malicious webpage that automatically uploads files from common locations such as documents folders, browser cache directories, or system configuration files, potentially exposing sensitive information or creating backdoor access points. The vulnerability specifically affects users who browse the internet with Opera versions 6.0.1 and 6.0.2, making them susceptible to attacks when visiting compromised websites or clicking on malicious links that trigger the exploit.
This vulnerability can be categorized under CWE-22 as "Improper Limitation of a Pathname to a Restricted Directory" and relates to CWE-74 as "Improper Neutralization of Special Elements in Output Used by a Downstream Component." The attack pattern aligns with TTPs described in the MITRE ATT&CK framework under technique T1190 "Exploit Public-Facing Application" and T1059 "Command and Scripting Interpreter" as attackers can leverage this vulnerability to execute unauthorized file operations. Organizations should immediately update to newer versions of Opera browsers where this vulnerability has been patched, implement proper input validation on web applications, and educate users about the risks of visiting untrusted websites. Network administrators should also consider implementing web application firewalls to detect and block malicious file upload attempts that include newline characters in file path values.