Description

A vulnerability in the email parsing of Cisco AsyncOS Software for Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to execute arbitrary commands with root privileges on the underlying operating system. This vulnerability is due to insufficient validation in the email parsing logic. An attacker could exploit this vulnerability by sending a crafted email message that contains malicious SQL statements through an affected device. A successful exploit could allow the attacker to execute arbitrary SQL statements, leading to command execution with root privileges on the underlying operating system.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-09-14T17:17:51.113Z",
  "pubdate": "2026-09-14T17:17:51.113Z",
  "executiveSummary": "This vulnerability involves an unauthenticated remote command execution flaw within Cisco AsyncOS Software for Cisco Secure Email Gateway. The issue stems from insufficient input validation within the email parsing logic, which allows for the injection of malicious SQL statements.\nBy submitting a crafted email, an attacker can trigger a SQL injection attack that subsequently facilitates arbitrary command execution with root privileges on the underlying operating system. This represents a critical security risk as it permits full system compromise, data exfiltration, or complete service disruption.\nThe vulnerability requires no authentication and is remotely exploitable, making it a high-priority target for threat actors. Successful exploitation grants the attacker unrestricted control over the affected appliance, bypassing standard security boundaries inherent in the email gateway's architecture. Organizations using the affected software are at severe risk if the appliance is internet-facing or exposed to untrusted traffic sources.",
  "technicalDetails": "The vulnerability originates from the email parsing subsystem of Cisco AsyncOS Software, which fails to adequately sanitize or parameterize input prior to interacting with backend database queries. This flaw is classified as a SQL injection vulnerability that acts as a pivot point for escalation into OS-level command injection.\nThe attack flow begins when an attacker transmits a maliciously crafted email to a Cisco Secure Email Gateway. The email parser, tasked with processing incoming message headers or body content, processes the input using insecure string concatenation or inadequate escaping mechanisms when constructing internal database queries. This allows the attacker to break out of the intended query context by injecting arbitrary SQL syntax.\nThe exploitation process leverages the application's database interaction to execute commands. When the malicious SQL payload is processed, it forces the database layer to interface with operating system primitives—likely through system-level stored procedures or extended integration modules—that permit the execution of binary commands or shell scripts. Because the service responsible for parsing email messages operates with high-level system permissions, the resulting command execution inherits root-level privileges.\nThe post-exploitation phase allows an attacker to achieve full administrative control over the appliance. With root access, an attacker can install persistent backdoors, intercept sensitive email traffic, modify configuration settings, or pivot into the internal network infrastructure. Furthermore, as the vulnerability resides within the parsing logic, it can be triggered repeatedly without requiring prior knowledge of the internal system architecture, as the gateway must process arbitrary, untrusted data by design.\nThe severity of this issue is amplified by the lack of authentication required for exploitation. The attack surface is exposed to any entity capable of sending an email through the device's SMTP listener. Because the gateway is designed to accept and process email from external sources, the network exposure is inherent to the appliance's core function. There is no requirement for the attacker to have valid credentials or prior interaction with the management console of the device."
}