CVE-2007-6059 in Javamail
Summary
by MITRE
** DISPUTED ** Javamail does not properly handle a series of invalid login attempts in which the same e-mail address is entered as username and password, and the domain portion of this address yields a Java UnknownHostException error, which allows remote attackers to cause a denial of service (connection pool exhaustion) via a large number of requests, resulting in a SQLNestedException. NOTE: Sun disputes this issue, stating "The report makes references to source code and files that do not exist in the mentioned products."
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Analysis
by VulDB Data Team • 08/08/2024
The vulnerability described in CVE-2007-6059 relates to a potential denial of service condition within JavaMail implementations that occurs during authentication processing. This issue manifests when attackers exploit a specific pattern of invalid login attempts where the same email address is submitted as both username and password, with the domain portion of this address triggering a Java UnknownHostException error. The vulnerability is categorized as disputed by Sun Microsystems, which has stated that the reported source code references and files do not exist within the mentioned products, creating uncertainty about the validity of the reported exploit mechanism.
The technical flaw involves improper error handling within the JavaMail authentication process where the system fails to adequately manage connection pool resources when encountering repeated invalid login attempts. When the same email address is used for both authentication fields and the domain resolution generates an UnknownHostException, the system's response mechanism becomes problematic. This condition can lead to connection pool exhaustion as the system attempts to process multiple failed authentication requests without proper resource cleanup or rate limiting mechanisms. The cascading effect of these failed attempts can ultimately result in SQLNestedException errors, indicating that the underlying database connection management is also affected by the resource exhaustion.
From an operational perspective, this vulnerability represents a significant denial of service threat that could impact email server availability and system performance. The attack vector requires a large number of malicious requests to be effective, making it a resource-intensive attack that could overwhelm server capacity. The connection pool exhaustion scenario means that legitimate users would be unable to establish new connections to the email service, effectively blocking normal email operations. The cascading nature of the vulnerability, where initial connection issues lead to database-level exceptions, demonstrates how a single authentication flaw can propagate through multiple system layers and amplify the overall impact of the attack.
Security practitioners should consider this vulnerability in the context of proper input validation and authentication error handling mechanisms. The issue aligns with CWE-20, which addresses improper input validation, and could potentially map to ATT&CK techniques related to resource exhaustion and denial of service operations. Organizations should implement robust rate limiting and connection pooling management strategies to prevent such attacks from depleting system resources. Additionally, proper error handling should ensure that authentication failures do not lead to resource leaks or cascading failures that could affect database connectivity and overall system stability.
Despite Sun's dispute regarding the specific implementation details, the vulnerability concept remains relevant to understanding authentication security patterns in email systems. The underlying principles of improper error handling and resource management remain valid security concerns that should be addressed through comprehensive security testing and proper implementation of connection management protocols. The disputed nature of the vulnerability highlights the importance of thorough verification and validation of security reports, while also emphasizing that the fundamental security concepts around resource exhaustion and authentication error handling remain applicable to modern system design and implementation practices.