CVE-2000-1234 in Phorum
Summary
by MITRE
violation.php3 in Phorum 3.0.7 allows remote attackers to send e-mails to arbitrary addresses and possibly use Phorum as a "spam proxy" by setting the Mod and ForumName parameters.
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Analysis
by VulDB Data Team • 01/11/2025
The vulnerability described in CVE-2000-1234 resides within the Phorum 3.0.7 web-based discussion forum software, specifically in the violation.php3 script. This represents a classic example of insecure input validation and improper access control that enables malicious actors to exploit the system's email functionality for unauthorized purposes. The flaw manifests when remote attackers manipulate the Mod and ForumName parameters, which are typically used for administrative functions and forum identification respectively. The vulnerability falls under the category of improper input validation as defined by CWE-20, where the application fails to properly sanitize user-supplied data before processing it.
The technical exploitation of this vulnerability occurs through parameter manipulation that bypasses normal email sending restrictions within the Phorum system. When attackers set the Mod and ForumName parameters, they can effectively coerce the forum software into sending emails to arbitrary recipient addresses without proper authentication or authorization. This misconfiguration allows the system to function as an unauthorized email relay, enabling spammers to leverage the legitimate forum infrastructure to distribute unwanted messages. The vulnerability essentially removes the checks that would normally prevent unauthorized email transmission, creating an open relay condition that violates standard email security practices. This type of vulnerability is particularly dangerous because it can be exploited by attackers without requiring any special privileges or authentication credentials.
The operational impact of this vulnerability extends beyond simple spam distribution, as it represents a significant security risk for organizations using Phorum 3.0.7. The system can be weaponized as a spam proxy, where malicious actors use the legitimate forum's reputation and infrastructure to send phishing emails, spam campaigns, or other unwanted communications. This exploitation can lead to the forum server being blacklisted by email providers, resulting in legitimate users being unable to send emails through the compromised system. The vulnerability also poses risks to the organization's reputation and can result in legal implications if the spam distribution is traced back to their infrastructure. From an attacker's perspective, this represents a low-effort, high-impact method of conducting email-based attacks while maintaining plausible deniability due to the legitimate-looking nature of the emails being sent.
Mitigation strategies for this vulnerability require immediate patching of the affected Phorum version to address the input validation flaws. Organizations should implement proper parameter sanitization and input validation mechanisms to ensure that all user-supplied data is properly checked before being processed by the application. The implementation of access control measures is essential to restrict email functionality to authorized users only, preventing unauthorized use of the forum's email capabilities. Network-level protections such as email filtering and monitoring systems can help detect and prevent abuse of the compromised functionality. Additionally, organizations should consider implementing rate limiting and email destination validation to prevent bulk email sending through the system. This vulnerability aligns with ATT&CK technique T1192, which describes the use of compromised systems for spam distribution, and demonstrates the importance of proper input validation and access control as outlined in security frameworks such as the OWASP Top Ten. The remediation process should include comprehensive security testing to ensure that similar vulnerabilities are not present in other parts of the application, as this type of input manipulation can potentially affect multiple components within web applications.