CVE-2006-4379: Ipswitch IMail SMTP daemon stack buffer overflow via crafted address string

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 19 September 2026. Confidence: medium.

high priorityRemote, unauthenticated code execution in an internet-facing mail service with a high EPSS score warrants prompt patching despite the absence of KEV listing.

What it is

The SMTP daemon in Ipswitch Collaboration Suite 2006 (Premium and Standard), IMail, IMail Plus and IMail Secure contains a stack-based buffer overflow triggered by a long string placed after an '@' and before a ':' character. A remote, unauthenticated attacker can send a crafted SMTP command to corrupt memory and potentially execute arbitrary code on the mail server. The record does not specify affected version numbers beyond the 2006 product names.

Impact

Successful exploitation gives the attacker remote code execution in the context of the SMTP daemon, which typically runs with elevated privileges on the mail host. That can lead to full compromise of the mail server and any credentials or mail data it holds.

Attack surface

Reachable over the network through the SMTP service; the CVSS vector AV:N/AC:L/Au:N indicates no authentication and no user interaction are required. The attacker only needs to deliver a malformed address-like string in an SMTP exchange.

Exploitation

The CVE is not listed in CISA KEV and no ransomware use is documented, but EPSS is high at roughly 0.61 (99th percentile), and multiple references carry Patch tags, indicating vendor fixes exist. No public exploit code is confirmed by the supplied references.

What to do

• Apply the vendor patches referenced by Ipswitch (ics20061.asp for Collaboration Suite and im20061.asp for IMail) as the first action.
• If patching is not immediately possible, restrict SMTP access to trusted mail relays and block inbound port 25/587 from untrusted networks.
• Run the SMTP daemon under a least-privileged service account and enable OS-level exploit mitigations such as DEP and ASLR.
• Monitor vendor advisories for the affected 2006 product lines and plan upgrade or retirement of unsupported versions.

Detection

• Inspect SMTP logs for malformed address strings containing an unusually long segment between '@' and ':' characters.
• Alert on SMTP daemon crashes or restarts, which may indicate failed exploitation attempts.
• Watch for unexpected child processes or outbound connections spawned by the SMTP service process.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.