CVE-2023-0655 in Email Security
Summary
by MITRE • 02/14/2023
SonicWall Email Security contains a vulnerability that could permit a remote unauthenticated attacker access to an error page that includes sensitive information about users email addresses.
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Analysis
by VulDB Data Team • 07/12/2025
The vulnerability identified as CVE-2023-0655 resides within SonicWall Email Security appliances, representing a critical information disclosure flaw that undermines the security posture of email infrastructure. This weakness allows remote attackers to access error pages containing sensitive user email address information without requiring authentication credentials, effectively bypassing traditional access controls that should protect such data. The vulnerability manifests when the system generates error responses that inadvertently expose user email addresses within error page content, creating a direct avenue for attackers to harvest this information for further malicious activities.
From a technical perspective, the flaw stems from improper handling of error conditions within the email security appliance's web interface. When system errors occur during user authentication or access attempts, the error pages are configured to display user email addresses as part of diagnostic information. This configuration violates fundamental security principles of least privilege and information hiding, where system internals should not reveal sensitive user data even in error conditions. The vulnerability aligns with CWE-200, which addresses improper exposure of sensitive information, and represents a classic case of insufficient error handling that exposes system internals to unauthorized users.
The operational impact of this vulnerability extends beyond simple information disclosure, creating potential vectors for targeted attacks and social engineering campaigns. Attackers can systematically probe the system to identify valid email addresses, which can then be used for credential stuffing attacks against user accounts, phishing campaigns, or to build comprehensive user directories for more sophisticated attacks. The unauthenticated nature of the exploit means that any remote attacker can leverage this vulnerability without requiring prior access or credentials, making it particularly dangerous in environments where email security appliances serve as primary email gateways for organizations. This vulnerability directly impacts the confidentiality aspect of the CIA triad and can facilitate privilege escalation attempts when combined with other reconnaissance data.
Organizations utilizing SonicWall Email Security appliances should implement immediate mitigations including configuration changes to prevent error pages from displaying user email addresses, enabling comprehensive logging and monitoring of error conditions, and implementing network segmentation to limit access to these systems. The remediation strategy should align with ATT&CK framework tactic TA0007 (Discovery) by ensuring that reconnaissance activities cannot easily extract user email information. Additional protective measures include deploying web application firewalls to filter error page content, implementing proper input validation to prevent error conditions that expose sensitive data, and conducting regular security assessments to identify similar information disclosure vulnerabilities across the email infrastructure stack. Organizations should also consider implementing rate limiting and access controls on the email security appliance's web interface to prevent automated probing of error conditions that could reveal additional sensitive information.