CVE-2018-14357 in Mutt
Summary
by MITRE
An issue was discovered in Mutt before 1.10.1 and NeoMutt before 2018-07-16. They allow remote IMAP servers to execute arbitrary commands via backquote characters, related to the mailboxes command associated with an automatic subscription.
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Analysis
by VulDB Data Team • 04/09/2023
This vulnerability affects the mutt and neomutt email clients, specifically exposing a command injection flaw in versions prior to 1.10.1 and 2018-07-16 respectively. The issue stems from improper handling of backquote characters within IMAP server responses during mailbox subscription operations, creating a path for remote code execution through crafted server responses.
The technical flaw exists in the mailboxes command implementation where the software fails to properly sanitize or escape backquote characters that may appear in IMAP server responses. When the email client automatically subscribes to mailboxes, it processes server responses containing these special characters without adequate input validation, allowing attackers to inject arbitrary commands that get executed within the context of the email client process.
This vulnerability operates at the application layer and represents a critical security risk as it enables remote attackers to execute arbitrary commands on systems running vulnerable versions of mutt or neomutt. The attack requires an attacker to control or compromise an IMAP server that the victim's email client connects to, typically through a malicious email server or man-in-the-middle attack scenario. The impact extends beyond simple command execution to potentially allow full system compromise, privilege escalation, and data exfiltration.
The vulnerability aligns with CWE-78 Improper Neutralization of Special Elements used in OS Command Execution, which is categorized under the broader category of command injection flaws. It also maps to ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell, though more broadly represents a general command injection vulnerability. The attack vector requires a compromised IMAP server to deliver malicious responses containing backquote characters that trigger the command execution path.
Organizations using mutt or neomutt should immediately upgrade to versions 1.10.1 or later for mutt and the corresponding neomutt release from July 16 2018 or later. System administrators should also implement network monitoring to detect unusual IMAP traffic patterns and consider implementing additional security controls such as email filtering and network segmentation to limit exposure. The fix involves proper input sanitization and escaping of special characters in IMAP response processing, particularly around backquote characters used in command execution contexts.