Cisco security advisory (AV26-921)

Cisco AsyncOS Software for Cisco Secure Email Gateway contains a SQL injection flaw (CWE-89) in its email parsing logic, caused by insufficient validation of message content. An unauthenticated, remote attacker can trigger it simply by sending a crafted email containing malicious SQL statements through an affected gateway, with no user interaction required. Successful exploitation allows arbitrary SQL execution that escalates to arbitrary operating-system command execution with root privileges, fully compromising the appliance and all mail flowing through it. Any organization running an affected version of Cisco Secure Email Gateway is impacted, and because these appliances sit on the inbound mail path they are inherently reachable over the network. There is no known public proof-of-concept, the flaw is not on the CISA KEV list, and no in-the-wild exploitation has been reported to date, though the CVSS 9.8 rating makes patching urgent.

Do: Upgrade to the fixed AsyncOS release listed in the corresponding Cisco PSIRT advisory as soon as possible, since the flaw is unauthenticated, requires no user interaction, and yields root. Until patched, apply any Cisco-documented workarounds and tightly restrict which hosts can submit mail to the gateway where operationally feasible. Review mail and system logs on these appliances for anomalies such as SQL errors in parsing, unexpected processes, or unexplained outbound connections that could indicate exploitation attempts.