CVE-2002-1917 in GeekLog
Summary
by MITRE
CRLF injection vulnerability in the "User Profile: Send Email" feature in Geeklog 1.35 and 1.3.5sr1 allows remote attackers to obtain e-mail addresses by injecting a CRLF into the Subject field and adding a BCC mail header.
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Analysis
by VulDB Data Team • 09/01/2025
The CVE-2002-1917 vulnerability represents a classic cross-site scripting and email header injection flaw that affected the Geeklog content management system version 1.35 and 1.3.5sr1. This vulnerability specifically targets the User Profile Send Email functionality, which is a core feature allowing users to communicate with each other through the system's built-in messaging capabilities. The flaw stems from inadequate input validation and sanitization within the email composition interface, creating an exploitable condition where malicious actors can manipulate the email headers through crafted input.
The technical implementation of this vulnerability relies on the manipulation of Carriage Return Line Feed sequences within the email subject field. When an attacker injects CRLF characters into the subject line, these sequences can be interpreted by the email processing system as command delimiters rather than part of the message content. This injection technique allows attackers to append additional email headers such as BCC (blind carbon copy) fields, effectively bypassing normal email security measures and enabling unauthorized email address harvesting. The vulnerability specifically exploits the lack of proper sanitization of user input before it is processed and included in the email headers, creating a pathway for attackers to extract sensitive email address information from the system's user database.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to harvest email addresses from the Geeklog user base and potentially use this information for spam campaigns, phishing attacks, or social engineering operations. The ability to inject BCC headers means that attackers can send emails to multiple recipients without the knowledge of the original recipients, creating a vector for mass email distribution while maintaining anonymity. This vulnerability particularly affects systems where Geeklog serves as a community platform or portal, as the user email addresses become exposed through this injection mechanism, potentially compromising user privacy and security. The vulnerability is classified under CWE-116 as improper encoding or escaping of output, and aligns with ATT&CK technique T1566 for social engineering through email manipulation.
Mitigation strategies for CVE-2002-1917 require immediate implementation of input validation and sanitization measures within the email processing components of the Geeklog system. The most effective approach involves implementing strict validation of user input in email subject fields, specifically filtering out or encoding CRLF characters before they are processed in email headers. System administrators should also consider implementing proper output encoding for all user-generated content that will be included in email headers, ensuring that special characters are properly escaped to prevent header injection attacks. Additionally, the system should enforce strict email header validation and reject any email submissions that contain suspicious header injection patterns. The vulnerability demonstrates the critical importance of input validation in web applications and highlights the need for comprehensive security measures that address both client-side and server-side data handling to prevent such header injection attacks from compromising system security and user privacy.