CVE-2017-14461 in Dovecot
Summary
by MITRE
A specially crafted email delivered over SMTP and passed on to Dovecot by MTA can trigger an out of bounds read resulting in potential sensitive information disclosure and denial of service. In order to trigger this vulnerability, an attacker needs to send a specially crafted email message to the server.
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Analysis
by VulDB Data Team • 02/16/2023
This vulnerability resides within the Dovecot email server software and represents a critical out-of-bounds memory read flaw that can be exploited through the Simple Mail Transfer Protocol. The vulnerability manifests when Dovecot receives email messages that have been passed through a Mail Transfer Agent, allowing an attacker to craft malicious email content that triggers memory access violations. The flaw occurs during the processing of email headers or content where the application fails to properly validate input boundaries, leading to unauthorized memory access patterns that can expose sensitive data from the server's memory space.
The technical implementation of this vulnerability stems from inadequate bounds checking within Dovecot's email parsing routines, specifically when handling malformed email headers or content structures. This type of flaw falls under the CWE-125 vulnerability category, which encompasses out-of-bounds read conditions that can result in information disclosure and system instability. When an attacker crafts an email with carefully constructed header values or content that exceeds expected buffer sizes, the parsing logic fails to validate these inputs properly, causing the application to read memory locations beyond the allocated buffers. The ATT&CK framework categorizes this as a memory corruption technique that can be leveraged for information disclosure and denial of service operations.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential system availability issues. An attacker can exploit this weakness to extract sensitive information such as memory addresses, cryptographic keys, or user credentials that may be stored in adjacent memory locations. Additionally, the out-of-bounds read can cause the Dovecot process to crash or become unresponsive, resulting in denial of service for legitimate email services. This vulnerability affects organizations that rely on Dovecot as their mail server solution and can be particularly damaging in environments where email services are critical for business operations or where sensitive communications are processed through the affected system.
The exploitation of this vulnerability requires minimal privileges since it can be triggered through standard email delivery mechanisms, making it particularly dangerous in environments where email servers are exposed to untrusted networks. Organizations should prioritize patching this vulnerability immediately as the attack surface is broad and the potential for automated exploitation exists. The recommended mitigation strategy involves applying the vendor-provided security patches that address the bounds checking issues within the email parsing components. Network segmentation and email filtering solutions can provide additional layers of protection by implementing stricter email validation rules and monitoring for suspicious email patterns that may indicate exploitation attempts.