CVE-2006-3477 in CommuniGate
Summary
by MITRE
Unspecified vulnerability in the POP service in Stalker CommuniGate Pro 5.1c1 and earlier allows remote attackers to cause a denial of service (server crash) via unspecified vectors involving opening an empty inbox.
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Analysis
by VulDB Data Team • 06/22/2019
The vulnerability described in CVE-2006-3477 represents a critical denial of service flaw within the POP service implementation of Stalker CommuniGate Pro versions 5.1c1 and earlier. This vulnerability specifically manifests when remote attackers exploit weaknesses in how the system handles mailbox operations, particularly when attempting to open an empty inbox. The unspecified nature of the attack vectors suggests that multiple pathways could potentially trigger the same outcome, making the vulnerability particularly concerning for security professionals who must account for various potential attack surfaces.
The technical flaw resides in the POP service's insufficient input validation and error handling mechanisms when processing mailbox requests. When a remote attacker attempts to access an empty inbox through the POP protocol, the system fails to properly manage this specific condition, leading to a complete service crash. This behavior aligns with common software design flaws categorized under CWE-20, which addresses "Improper Input Validation," and CWE-116, which covers "Improper Encoding or Escaping of Output." The vulnerability demonstrates a classic lack of robust error handling that could be exploited to disrupt legitimate service availability.
From an operational impact perspective, this vulnerability poses significant risks to organizations relying on CommuniGate Pro for their email infrastructure. A successful exploitation could result in complete service disruption, affecting email communication for all users within the affected domain. The remote nature of the attack means that threat actors need only access to the network to potentially cause service outages, making this particularly dangerous in environments where email availability is critical. The vulnerability could be leveraged as part of broader attack campaigns targeting email infrastructure, potentially serving as an initial foothold for more sophisticated attacks or simply as a tool for disrupting business operations.
Organizations should implement immediate mitigations including upgrading to versions of CommuniGate Pro that address this vulnerability, as well as deploying network-level protections such as firewall rules that limit access to POP service ports from trusted networks only. The ATT&CK framework categorizes this type of vulnerability under T1499, which covers "Endpoint Denial of Service," and T1566, which addresses "Phishing," as attackers might use such vulnerabilities as part of broader campaigns. Additionally, implementing proper logging and monitoring of POP service access patterns can help detect anomalous behavior that might indicate exploitation attempts, while regular security assessments should be conducted to identify similar vulnerabilities in other email service implementations.