CVE-2001-0473 in Mutt
Summary
by MITRE
Format string vulnerability in Mutt before 1.2.5 allows a remote malicious IMAP server to execute arbitrary commands.
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Analysis
by VulDB Data Team • 06/25/2021
The vulnerability identified as CVE-2001-0473 represents a critical format string flaw in the Mutt email client software prior to version 1.2.5. This vulnerability specifically affects the IMAP protocol implementation within Mutt, creating a remote code execution vector that can be exploited by malicious IMAP servers. The flaw arises from improper input validation and handling of format specifiers in user-supplied data, particularly when processing email headers and other IMAP server responses. When Mutt processes data from an untrusted IMAP server, it fails to properly sanitize format string arguments, leading to potential arbitrary code execution on the victim's system.
The technical exploitation of this vulnerability occurs through carefully crafted IMAP server responses that contain malicious format specifiers. These specifiers can be embedded within email headers, subject lines, or other user-controllable data fields that Mutt processes during IMAP communication. The vulnerability maps to CWE-134, which specifically addresses format string vulnerabilities where format strings are constructed from user-controlled data. This weakness enables attackers to manipulate the printf family of functions and potentially overwrite memory locations, leading to arbitrary code execution. The attack vector is particularly dangerous because it requires no local privileges and can be executed remotely through a compromised or malicious IMAP server.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass full system compromise when exploited successfully. An attacker controlling an IMAP server can execute arbitrary commands with the privileges of the user running Mutt, potentially leading to complete system infiltration. This vulnerability affects organizations relying on Mutt for email management and poses significant risk in environments where users may unknowingly connect to compromised IMAP servers. The vulnerability can be exploited through various attack techniques that align with ATT&CK framework tactics including TA0002 (Execution) and TA0006 (Credential Access), as successful exploitation can lead to privilege escalation and credential theft. The impact is particularly severe in enterprise environments where Mutt is used for email communication and may be exposed to untrusted external servers.
Mitigation strategies for CVE-2001-0473 primarily focus on immediate software updates and configuration hardening. Organizations should immediately upgrade to Mutt version 1.2.5 or later, which contains the necessary patches to address the format string vulnerability. Additional protective measures include implementing strict IMAP server certificate validation, disabling automatic IMAP server connections, and configuring Mutt to use secure communication protocols. Network-level protections such as firewalls and intrusion detection systems can help monitor for suspicious IMAP traffic patterns. Security practitioners should also consider implementing email filtering solutions that can detect and block malicious IMAP responses before they reach the Mutt client. Regular security audits and vulnerability assessments should be conducted to ensure that all email client software remains up to date and properly configured to prevent exploitation of similar format string vulnerabilities.