CVE-2003-1541 in Guestbook
Summary
by MITRE
PlanetMoon Guestbook tr3.a stores sensitive information under the web root with insufficient access control, which allows remote attackers to obtain the admin script password, and other passwords, via a direct request to files/passwd.txt.
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Analysis
by VulDB Data Team • 07/13/2025
The vulnerability described in CVE-2003-1541 represents a critical security flaw in the PlanetMoon Guestbook application version tr3.a that directly violates fundamental web application security principles. This issue stems from improper access control mechanisms that allow unauthorized remote attackers to directly access sensitive configuration files containing administrative credentials and user passwords. The vulnerability specifically affects the application's handling of the files/passwd.txt file which is stored within the web root directory, making it directly accessible through standard web requests without proper authentication or authorization checks. This misconfiguration creates an immediate and severe security risk as it eliminates any form of access control enforcement that should normally protect sensitive administrative resources from public exposure.
The technical implementation of this vulnerability demonstrates a classic case of insecure direct object reference, where the application fails to validate access permissions before serving sensitive files. The flaw occurs because the passwd.txt file containing administrative and user credentials is stored in a location that is directly accessible via HTTP requests, effectively bypassing any application-level security controls. This type of vulnerability is categorized under CWE-284 which specifically addresses inadequate access control mechanisms, and it directly aligns with ATT&CK technique T1078 which covers valid accounts and credential access through exploitation of weak access controls. The vulnerability exists at the application layer where the web server configuration or application code fails to properly restrict access to sensitive files, allowing attackers to enumerate and retrieve credentials through simple URL manipulation.
The operational impact of this vulnerability is severe and far-reaching, as it provides attackers with immediate access to administrative credentials that can be used to completely compromise the guestbook application and potentially the underlying system. Once an attacker obtains the admin script password, they gain full control over the guestbook functionality including the ability to modify entries, delete content, add malicious entries, and potentially escalate privileges to gain broader system access. The exposure of additional passwords within the passwd.txt file further compounds the risk, as these credentials might be reused across multiple systems or applications, creating a potential chain of compromise. This vulnerability also enables persistent access to the system, as attackers can maintain their compromised state indefinitely without requiring additional authentication mechanisms to be bypassed. The impact extends beyond just the immediate application as these credentials could be leveraged for lateral movement within networks where the same passwords are used across multiple services.
Mitigation strategies for this vulnerability must address both the immediate exposure and the underlying architectural issues that allowed the problem to occur. The primary remediation involves moving sensitive configuration files outside the web root directory and implementing proper access control mechanisms that enforce authentication and authorization checks before serving any sensitive content. This approach directly addresses the CWE-284 vulnerability by ensuring that access controls are properly enforced and prevents unauthorized users from directly accessing sensitive files through simple HTTP requests. Organizations should also implement proper file permissions and web server configurations that prevent direct access to sensitive files while maintaining proper application functionality. Additionally, regular security audits and penetration testing should be conducted to identify similar misconfigurations in other applications and systems, as this type of vulnerability is commonly found in legacy applications that have not been properly secured. The remediation process should also include credential rotation for any compromised accounts and implementation of monitoring to detect unauthorized access attempts to sensitive files, which aligns with ATT&CK techniques for defense evasion and credential access.