CVE-2004-2766 in One Messaging Server
Summary
by MITRE
Webmail in Sun ONE Messaging Server 6.1 and iPlanet Messaging Server 5.2 before 5.2hf2.02 allows remote attackers to obtain unspecified "access" to e-mail via a crafted e-mail message, related to a "session hijacking" issue, a different vulnerability than CVE-2005-2022 and CVE-2006-5486.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 04/29/2026
The vulnerability identified as CVE-2004-2766 represents a critical session hijacking flaw within the Webmail functionality of Sun ONE Messaging Server 6.1 and iPlanet Messaging Server 5.2 versions prior to 5.2hf2.02. This security weakness specifically targets the authentication and session management mechanisms of these messaging servers, creating opportunities for remote attackers to gain unauthorized access to email accounts without proper credentials. The vulnerability stems from insufficient validation of session identifiers and authentication tokens within the email processing pipeline, allowing malicious actors to exploit crafted email messages to manipulate session states and potentially access other users' email accounts. Such issues fall under the broader category of session management vulnerabilities classified as CWE-613, which addresses insufficient session expiration and weak session identifiers. The impact extends beyond simple unauthorized access as this vulnerability enables attackers to potentially intercept and manipulate email communications, compromise user privacy, and potentially escalate privileges within the messaging environment.
The technical exploitation of this vulnerability occurs through the careful crafting of email messages that contain malicious session identifiers or authentication tokens designed to bypass normal authentication procedures. Attackers can construct specially formatted emails that, when processed by the vulnerable messaging server, trigger improper session handling mechanisms. This allows unauthorized users to establish valid sessions within the email system, effectively hijacking existing user sessions and gaining access to their mailboxes. The vulnerability is particularly concerning because it operates at the application layer, leveraging the legitimate email processing functionality to execute unauthorized access attempts. The attack vector is entirely remote, requiring no physical access to the server or direct network compromise, making it highly dangerous in networked environments where email servers are exposed to external networks. This type of attack pattern aligns with the attack techniques described in the MITRE ATT&CK framework under the T1190 category, which covers exploitation of remote services through crafted inputs.
The operational impact of CVE-2004-2766 extends significantly beyond immediate unauthorized access, creating potential for widespread data compromise within organizations relying on affected messaging servers. Organizations using these vulnerable versions face risks including unauthorized email reading, message interception, account takeover, and potential data exfiltration. The vulnerability's persistence means that once exploited, attackers can maintain access for extended periods without detection, potentially compromising sensitive corporate communications, personal information, and confidential business data. The session hijacking nature of this vulnerability also creates challenges for network monitoring and detection, as the malicious activity can appear to originate from legitimate user sessions, making it difficult to distinguish between normal user behavior and compromised access. Security administrators must consider the broader implications for email-based security controls, including the potential for this vulnerability to undermine other security measures such as email encryption, digital signatures, and access control policies that depend on proper session management.
Mitigation strategies for CVE-2004-2766 primarily focus on immediate software updates and patches provided by Sun Microsystems and iPlanet to address the session management flaws in their messaging servers. Organizations should prioritize applying the 5.2hf2.02 hotfix or equivalent updates that specifically address the session hijacking vulnerability in the affected versions. Additionally, implementing network-level security controls such as email filtering systems, intrusion detection/prevention systems, and monitoring for unusual email processing patterns can help detect potential exploitation attempts. Security configurations should include enhanced session timeout mechanisms, stronger session identifier generation, and regular session validation checks to prevent unauthorized access. Network segmentation and access controls should be implemented to limit exposure of email servers to untrusted networks, while regular security audits and vulnerability assessments should be conducted to identify and remediate similar session management weaknesses. The remediation process should also include user education regarding suspicious email content and the importance of maintaining updated security software to prevent exploitation of such vulnerabilities that can compromise entire email infrastructure.