CVE-2014-0467 in Mutt
Summary
by MITRE
Buffer overflow in copy.c in Mutt before 1.5.23 allows remote attackers to cause a denial of service (crash) via a crafted RFC2047 header line, related to address expansion.
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Analysis
by VulDB Data Team • 05/08/2026
The vulnerability identified as CVE-2014-0467 represents a critical buffer overflow condition within the Mutt email client software, specifically within the copy.c module. This flaw affects versions prior to 1.5.23 and demonstrates a classic security weakness that has significant implications for email client security. The vulnerability manifests when the software processes RFC2047 encoded header lines, which are standard email encoding mechanisms used to handle non-ASCII characters in email headers. The buffer overflow occurs during address expansion operations, where the software attempts to parse and process email addresses contained within these encoded headers.
The technical implementation of this vulnerability involves improper bounds checking during the processing of crafted RFC2047 header content. When Mutt encounters a specially crafted header line containing encoded addresses, the copy.c module fails to validate the length of the input data against the allocated buffer space. This allows an attacker to provide input data that exceeds the allocated buffer boundaries, causing memory corruption that ultimately results in application crash. The vulnerability operates at the intersection of email protocol handling and memory management, making it particularly dangerous in environments where email clients process untrusted content from external sources.
From an operational impact perspective, this vulnerability creates a reliable denial of service condition that can be exploited by remote attackers without requiring any authentication or privileged access. The crash occurs during normal email processing operations, meaning that simply receiving an email message containing the malicious header line is sufficient to trigger the vulnerability. This makes the attack vector extremely accessible and the potential for disruption significant, particularly in environments where email clients are used as primary communication channels. The vulnerability affects not only individual users but also organizations that rely on automated email processing systems, as these systems could be rendered unavailable through simple email-based attacks.
The security implications extend beyond simple denial of service to demonstrate poor input validation practices that are commonly addressed by industry standards such as CWE-121, which catalogs buffer overflow vulnerabilities. This vulnerability aligns with ATT&CK technique T1204.002 related to legitimate program execution, as it exploits normal application behavior to cause unintended consequences. The flaw represents a failure in defensive programming practices and highlights the importance of implementing proper bounds checking and input validation mechanisms. Organizations should implement immediate patch management procedures to address this vulnerability, as the fix involves updating to Mutt version 1.5.23 or later, which contains the necessary code modifications to properly handle buffer boundaries during RFC2047 header processing. Additionally, administrators should consider implementing email filtering measures that can identify and quarantine suspicious header content as an additional defensive layer. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date software and implementing robust input validation practices to prevent exploitation of similar buffer overflow conditions in other applications.