Man-in-the-Middle (MitM) attack in Kerio Connect - CVE-2011-1506
Published: June 8, 2025
Vulnerability identifier: #VU110639
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2011-1506
CWE-ID: CWE-300
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to incorrect implementation of STARTTLS command. A remote attacker can insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place and perform MitM attack.
Affected software
Kerio Connect
How to mitigate CVE-2011-1506
Install updates from vendor's website.