CVE-2003-0979 in Visitorbook
Summary
by MITRE
FreeScripts VisitorBook LE (visitorbook.pl) does not properly escape line breaks in input, which allows remote attackers to (1) use VisitorBook as an open mail relay, when $mailuser is 1, via extra headers in the email field, or (2) cause the guestbook database to be deleted via a large number of line breaks that exceeds the $max_posts variable.
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Analysis
by VulDB Data Team • 06/17/2018
The vulnerability described in CVE-2003-0979 affects FreeScripts VisitorBook LE, a guestbook application that fails to properly sanitize input data containing line breaks. This weakness creates two distinct attack vectors that exploit the application's insufficient output escaping mechanisms. The primary concern arises from the application's handling of user-supplied data in the email field, which when combined with the $mailuser configuration parameter set to 1, enables malicious actors to manipulate email headers and utilize the system as an open relay. This represents a classic case of improper input validation where line break characters are not adequately escaped or filtered, allowing attackers to inject additional email headers that bypass normal mail delivery restrictions.
The second vulnerability manifests when attackers exploit the application's lack of input length validation and sanitization in the guestbook database handling. By submitting a carefully crafted payload containing an excessive number of line breaks, an attacker can exceed the $max_posts variable threshold, which triggers a condition that leads to the complete deletion of the guestbook database. This demonstrates a critical flaw in the application's data processing logic where boundary conditions are not properly enforced, allowing for arbitrary data manipulation through input manipulation. The vulnerability is particularly concerning as it combines both relay abuse and data destruction capabilities within a single flawed input handling mechanism.
From a cybersecurity perspective, this vulnerability aligns with CWE-116, which addresses improper encoding or escaping of output, and CWE-772, concerning missing release of resource after effective lifetime. The attack patterns associated with this vulnerability map to ATT&CK techniques including TA0011 (Command and Control) through open relay exploitation and TA0005 (Defense Evasion) via database destruction. The application's failure to implement proper input sanitization creates a pathway for attackers to leverage the guestbook system as both a communication relay and a data destruction vector, making it particularly dangerous in environments where such applications are deployed without proper network segmentation or monitoring controls.
Organizations should implement immediate mitigations including input validation at multiple layers, proper escaping of special characters in user input fields, and enforcement of strict boundary checks for database operations. The $max_posts variable should be properly validated against maximum allowable input lengths, and email field processing should include comprehensive header sanitization to prevent header injection attacks. Network-level protections such as email relay restrictions and monitoring for unusual database modification patterns should also be implemented. Additionally, the application should be updated to a newer version that properly handles input validation and escaping, as the vulnerability represents a fundamental flaw in the application's core security architecture that cannot be adequately patched through configuration changes alone.