CVE-2017-12639 in IMail Server
Summary
by MITRE
Stack based buffer overflow in Ipswitch IMail server up to and including 12.5.5 allows remote attackers to execute arbitrary code via unspecified vectors in IMmailSrv, aka ETRE or ETCTERARED.
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Analysis
by VulDB Data Team • 01/15/2021
The vulnerability identified as CVE-2017-12639 represents a critical stack-based buffer overflow within the Ipswitch IMail server software, affecting versions up to and including 12.5.5. This flaw resides in the IMailSrv component of the email server software, which is widely deployed in enterprise environments for handling email communications. The vulnerability has been historically referenced by security researchers under the aliases ETRE and ETCTERARED, indicating its significance within the cybersecurity community and its potential for widespread exploitation.
The technical nature of this buffer overflow stems from improper input validation within the IMailSrv service, where attacker-controlled data can be written beyond the bounds of allocated stack memory buffers. This occurs when the server processes specific network requests or commands without adequate bounds checking, allowing malicious input to overwrite adjacent memory locations including return addresses and control data. The vulnerability operates at the application layer, requiring network connectivity to exploit and presenting a remote attack surface that can be leveraged by adversaries without requiring local system access. According to CWE classification, this represents a classic stack-based buffer overflow vulnerability (CWE-121) that enables arbitrary code execution through memory corruption techniques.
The operational impact of this vulnerability extends far beyond simple denial of service scenarios, as it provides remote attackers with the capability to execute arbitrary code with the privileges of the IMail service account. This could result in complete system compromise, data exfiltration, and persistent access to enterprise networks. Organizations relying on IMail servers for email services face significant risk, as the vulnerability can be exploited through standard network protocols without requiring authentication or specialized knowledge of the system internals. The remote exploit nature means that attackers can target these systems from anywhere on the internet, making the vulnerability particularly dangerous in unpatched environments where the attack surface remains exposed.
Security professionals should immediately implement mitigations including applying the vendor-provided patches released in version 12.6.0 of the IMail server software, which address the buffer overflow conditions through proper input validation and memory management. Network segmentation and firewall rules should be implemented to restrict access to IMail server ports, particularly port 110 for POP3 and port 143 for IMAP services. Additionally, monitoring for unusual network traffic patterns or authentication attempts on these email services should be enabled to detect potential exploitation attempts. The vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under techniques related to remote code execution and privilege escalation, emphasizing the need for comprehensive defensive measures including application whitelisting and regular security assessments. Organizations should also consider implementing intrusion detection systems to monitor for exploitation attempts and maintain updated threat intelligence feeds to identify related malicious activity targeting this specific vulnerability.