CVE-2006-0447 in SPA-PRO Mail @Solomon
Summary
by MITRE
Multiple buffer overflows in E-Post Mail Server 4.10 and SPA-PRO Mail @Solomon 4.00 allow remote attackers to execute arbitrary code via a long username to the (1) AUTH PLAIN or (2) AUTH LOGIN SMTP commands, which is not properly handled by (a) EPSTRS.EXE or (b) SPA-RS.EXE; (3) a long username in the APOP POP3 command, which is not properly handled by (c) EPSTPOP4S.EXE or (d) SPA-POP3S.EXE; (4) a long IMAP DELETE command, which is not properly handled by (e) EPSTIMAP4S.EXE or (f) SPA-IMAP4S.EXE.
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Analysis
by VulDB Data Team • 08/02/2017
The vulnerability described in CVE-2006-0447 represents a critical buffer overflow issue affecting email server software components that handle authentication and command processing. This flaw exists in E-Post Mail Server version 4.10 and SPA-PRO Mail @Solomon version 4.00, specifically targeting the core executable processes responsible for handling various email protocols. The vulnerability stems from inadequate input validation mechanisms within the server's authentication handlers, where the software fails to properly sanitize user-supplied data before processing it in memory buffers of fixed size. These buffer overflows occur during the handling of standard email authentication protocols including SMTP AUTH PLAIN, SMTP AUTH LOGIN, POP3 APOP, and IMAP DELETE commands, making the affected systems susceptible to exploitation by remote attackers without requiring authentication.
The technical implementation of this vulnerability involves the exploitation of memory corruption through carefully crafted malicious input strings that exceed the allocated buffer space in the target executables. When the EPSTRS.EXE and SPA-RS.EXE processes receive excessively long usernames during SMTP authentication, or when EPSTPOP4S.EXE and SPA-POP3S.EXE encounter oversized usernames in APOP commands, or when EPSTIMAP4S.EXE and SPA-IMAP4S.EXE process malformed DELETE commands, the software's memory management fails to prevent buffer overflow conditions. This results in memory corruption that can be leveraged by attackers to overwrite adjacent memory locations, potentially allowing for arbitrary code execution with the privileges of the affected service processes. The vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers stack-based buffer overflow scenarios, making it a significant concern for system security.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as successful exploitation can lead to complete system compromise and unauthorized access to email communications. Attackers can leverage these buffer overflows to execute malicious code remotely, potentially gaining shell access to the affected mail servers and establishing persistent backdoors within the network infrastructure. This vulnerability particularly affects organizations that rely on these specific email server implementations, as the attack surface includes all email protocols supported by the vulnerable software versions. The remote nature of the exploit means that attackers do not require physical access to the systems or network credentials to attempt exploitation, making the vulnerability particularly dangerous in environments where email servers are exposed to the internet.
Mitigation strategies for this vulnerability must focus on immediate patching of the affected software versions, as no reliable workarounds exist for the buffer overflow conditions. Organizations should prioritize updating to patched versions of E-Post Mail Server 4.10 and SPA-PRO Mail @Solomon 4.00, or migrating to alternative email server solutions that have addressed these memory handling issues. System administrators should implement network segmentation to limit exposure of email servers to untrusted networks, while also deploying intrusion detection systems to monitor for exploitation attempts. The vulnerability aligns with ATT&CK technique T1190, which covers exploitation of remote services, and T1059, which covers command and scripting interpreter usage, making it a significant concern for both network security monitoring and incident response procedures. Additionally, implementing proper input validation mechanisms and memory protection features such as stack canaries, address space layout randomization, and data execution prevention can provide additional defense-in-depth measures against similar buffer overflow vulnerabilities.