CVE-2006-1255 in Mercur Messaging
Summary
by MITRE
Stack-based buffer overflow in the IMAP service in Mercur Messaging 5.0 SP3 and earlier allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a long string to the (1) LOGIN or (2) SELECT command, a different set of attack vectors and possibly a different vulnerability than CVE-2003-1177.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/15/2019
The vulnerability described in CVE-2006-1255 represents a critical stack-based buffer overflow flaw within the IMAP service of Mercur Messaging 5.0 SP3 and earlier versions. This vulnerability specifically affects the authentication and mailbox selection processes, creating a dangerous attack surface that remote adversaries can exploit to compromise system integrity. The flaw manifests when the IMAP service receives excessively long strings during LOGIN or SELECT command processing, allowing attackers to overwrite adjacent memory locations on the stack. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which occurs when a program writes more data to a buffer allocated on the stack than the buffer can hold, leading to memory corruption that can result in unpredictable behavior. This particular implementation flaw demonstrates a failure in proper input validation and bounds checking within the IMAP protocol handling components of the messaging server.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution, making it a severe security concern for organizations relying on Mercur Messaging services. When an attacker successfully exploits this buffer overflow, the application crash can be leveraged to execute arbitrary code with the privileges of the affected service account. The attack vectors involve sending maliciously crafted long strings to either the LOGIN or SELECT IMAP commands, which are fundamental operations in email client-server communication. This vulnerability differs from CVE-2003-1177, indicating that while both affect IMAP services, they represent distinct attack surfaces and underlying implementation flaws within the Mercur Messaging software. The stack-based nature of the overflow means that attackers can potentially overwrite return addresses and function pointers, enabling sophisticated exploitation techniques that align with ATT&CK technique T1059.007 for command and scripting interpreter execution.
Organizations utilizing Mercur Messaging 5.0 SP3 or earlier versions face significant risks from this vulnerability, as it provides attackers with a pathway to system compromise through standard email protocol interactions. The vulnerability's exploitation requires minimal privileges and can be automated, making it particularly dangerous in environments where email services are exposed to untrusted networks. Security professionals should prioritize immediate patching of affected systems, as the vulnerability represents a high-severity threat that can lead to complete system compromise. The recommended mitigation strategies include applying the vendor-supplied security patches, implementing network segmentation to limit exposure of IMAP services, and deploying intrusion detection systems to monitor for suspicious command sequences. Additionally, administrators should consider disabling unnecessary IMAP features, implementing strict input validation at network boundaries, and conducting regular security assessments to identify similar vulnerabilities in other messaging components. The vulnerability highlights the critical importance of proper input validation in network services and demonstrates how seemingly routine protocol operations can become attack vectors when proper security controls are absent.