CVE-2008-2049 in Mail Server
Summary
by MITRE
The POP3 server (EPSTPOP3S.EXE) 4.22 in E-Post Mail Server 4.10 allows remote attackers to obtain sensitive information via multiple crafted APOP commands for a known POP3 account, which displays the password in a POP3 error message.
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Analysis
by VulDB Data Team • 11/17/2017
The vulnerability described in CVE-2008-2049 represents a critical information disclosure flaw within the E-Post Mail Server 4.10 POP3 implementation. This security weakness specifically affects the EPSTPOP3S.EXE component version 4.22 and manifests through improper error handling mechanisms during authentication processes. The vulnerability exploits a fundamental flaw in how the system responds to malformed authentication requests, creating an avenue for remote attackers to extract sensitive credential information without requiring prior authentication access to the system.
The technical exploitation of this vulnerability occurs through carefully crafted APOP (Authentication/Authorization Protocol) commands that target known POP3 accounts within the mail server configuration. When the server receives these malformed requests, it fails to properly sanitize or validate the input before generating error responses. This inadequate input validation results in the server inadvertently revealing the actual password associated with the targeted account within the error message response. The flaw essentially transforms the authentication system from a security mechanism into a credential disclosure vector, as the server's defensive response becomes the attack's payload.
From an operational perspective, this vulnerability presents significant risk to organizations relying on E-Post Mail Server 4.10 for their email infrastructure. The remote nature of the attack means that threat actors can exploit this weakness from anywhere on the internet without requiring physical access or prior network compromise. The disclosure of passwords through error messages creates immediate credential compromise, potentially allowing attackers to gain full access to user mailboxes, conduct unauthorized email communications, and establish persistence within the network through legitimate email accounts. This vulnerability directly impacts the confidentiality and integrity of email communications, as it enables unauthorized access to sensitive information stored within the compromised accounts.
The security implications of this vulnerability align with CWE-200, which addresses "Information Exposure," and represents a classic example of how improper error handling can create security weaknesses. The flaw also maps to ATT&CK technique T1078.004, which covers "Valid Accounts: Cloud Accounts," as compromised credentials can be used to access email services. Organizations affected by this vulnerability should implement immediate mitigations including applying the vendor-provided patches, disabling unnecessary POP3 services, and implementing network segmentation to limit exposure. Additionally, monitoring for suspicious authentication patterns and implementing proper input validation measures across all network services can help prevent similar vulnerabilities from manifesting in other systems. The incident highlights the critical importance of secure error handling practices and demonstrates how seemingly benign system responses can become security threats when not properly designed with security in mind.