CVE-2003-1387 in Web Browser
Summary
by MITRE
Buffer overflow in Opera 6.05 and 6.06, and possibly other versions, allows remote attackers to execute arbitrary code via a URL with a long username.
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Analysis
by VulDB Data Team • 02/02/2025
The vulnerability identified as CVE-2003-1387 represents a critical buffer overflow flaw affecting Opera web browsers version 6.05 and 6.06, with potential impacts extending to other versions within the same release series. This security weakness stems from inadequate input validation mechanisms within the browser's URL parsing functionality, specifically when processing user credentials embedded within web addresses. The flaw manifests when the browser encounters a Uniform Resource Locator containing an excessively long username component, leading to memory corruption that adversaries can exploit to gain unauthorized code execution privileges on affected systems.
The technical implementation of this vulnerability resides in the browser's handling of authentication credentials within URLs, particularly when the username field exceeds the allocated buffer size. According to CWE-121, this constitutes a classic stack-based buffer overflow condition where attacker-controlled input data overflows into adjacent memory regions, potentially overwriting critical program execution structures including return addresses and function pointers. The vulnerability's exploitation pathway follows the typical remote code execution attack model where malicious actors craft specially formatted URLs designed to trigger the buffer overflow condition upon browser processing, thereby allowing arbitrary code injection into the target system's memory space.
Operationally, this vulnerability presents significant risk to users of affected Opera versions as it enables remote code execution without requiring any local privileges or user interaction beyond visiting a malicious website. The attack vector leverages the browser's automatic handling of URL credentials, making it particularly dangerous as users may unknowingly encounter compromised web content while browsing normally. The exploitability characteristics align with ATT&CK technique T1203, which describes the use of malicious web content to establish initial access through browser vulnerabilities, while also demonstrating aspects of T1059, where attackers leverage command execution capabilities to gain system control. The impact extends beyond simple code execution to potentially allow full system compromise, as successful exploitation could enable attackers to install persistent backdoors, escalate privileges, or exfiltrate sensitive data from the compromised browser environment.
Mitigation strategies for CVE-2003-1387 primarily focus on immediate software updates and patches provided by Opera to address the specific buffer overflow condition in the affected browser versions. System administrators should prioritize deployment of security patches to all Opera installations, particularly those running versions 6.05 and 6.06, while also considering temporary network-level restrictions that block access to potentially malicious URLs containing suspicious credential formats. Additional protective measures include implementing web application firewalls that can detect and block malformed URL patterns, enabling browser security features such as sandboxing and memory protection mechanisms, and conducting regular security assessments to identify any remaining vulnerable browser installations within network environments. Organizations should also consider implementing network monitoring solutions that can detect unusual traffic patterns associated with exploitation attempts and maintain comprehensive incident response procedures to address potential compromise scenarios resulting from successful exploitation of this vulnerability.