CVE-2018-10355 in Email Encryption Gateway
Summary
by MITRE
An authentication weakness vulnerability in Trend Micro Email Encryption Gateway 5.5 could allow an attacker to recover user passwords on vulnerable installations due to a flaw in the DBCrypto class. An attacker must first obtain access to the user database on the target system in order to exploit this vulnerability.
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Analysis
by VulDB Data Team • 02/08/2020
The vulnerability identified as CVE-2018-10355 represents a critical authentication weakness within Trend Micro Email Encryption Gateway version 5.5, specifically manifesting in the DBCrypto class implementation. This flaw creates a pathway for unauthorized password recovery attacks that could compromise user account security. The vulnerability requires an attacker to first gain access to the user database on the target system, establishing a prerequisite condition that aligns with common attack methodologies where initial access is obtained through other means before exploiting specific weaknesses. The DBCrypto class, responsible for database encryption and decryption operations, contains a design flaw that allows password recovery when the database is already compromised, making this vulnerability particularly dangerous in environments where database access might be achievable through other attack vectors.
The technical implementation of this vulnerability stems from improper handling of cryptographic operations within the DBCrypto class, which likely involves weak key derivation functions or predictable encryption patterns that enable attackers to reverse engineer stored password hashes or encrypted credentials. This weakness directly relates to CWE-327, which addresses broken or weak cryptographic algorithms, and may also connect to CWE-521, addressing weak password requirements or storage mechanisms. The vulnerability's exploitation requires an attacker to possess database-level access, which typically involves either gaining administrative credentials, exploiting database access controls, or utilizing other initial compromise techniques that would fall under the MITRE ATT&CK framework's initial access tactics. Once database access is achieved, the attacker can leverage this vulnerability to extract and recover user passwords without requiring additional authentication factors.
The operational impact of CVE-2018-10355 extends beyond simple password recovery, as it can enable attackers to establish persistent access to email systems and potentially escalate privileges within the organization's email infrastructure. This vulnerability particularly affects organizations that rely heavily on email encryption services, as compromised user credentials could lead to unauthorized access to sensitive communications and potential data breaches. The attack chain typically involves an initial compromise to gain database access, followed by exploitation of the DBCrypto class weakness to recover passwords, which then allows for further lateral movement within the network. Organizations using Trend Micro Email Encryption Gateway 5.5 are especially vulnerable if they have not implemented proper database access controls or if their database systems have weak access restrictions. The vulnerability's exploitation could lead to unauthorized email access, data exfiltration, and potential compromise of the entire email encryption infrastructure, making it a significant concern for enterprises that depend on secure email communications.
Mitigation strategies for this vulnerability require immediate attention to database access controls and encryption implementation. Organizations should implement robust database access controls, including proper user permissions, network segmentation, and monitoring of database access attempts. The Trend Micro Email Encryption Gateway should be updated to the latest version that addresses this specific vulnerability, as the vendor likely released a patch to correct the DBCrypto class implementation. Security measures should include regular database audits, monitoring for unauthorized access attempts, and implementation of multi-factor authentication for database administrative access. Additionally, organizations should consider implementing database activity monitoring tools that can detect anomalous access patterns and potential exploitation attempts. The remediation process should also include reviewing and strengthening password policies, ensuring that passwords are properly hashed with strong cryptographic functions, and implementing proper key management practices. Network segmentation strategies should be employed to limit database access to only authorized administrative systems, and regular security assessments should be conducted to identify and address similar cryptographic weaknesses in other components of the email infrastructure.