CVE-2003-0140 in Mutt
Summary
by MITRE
Buffer overflow in Mutt 1.4.0 and possibly earlier versions, 1.5.x up to 1.5.3, and other programs that use Mutt code such as Balsa before 2.0.10, allows a remote malicious IMAP server to cause a denial of service (crash) and possibly execute arbitrary code via a crafted folder.
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Analysis
by VulDB Data Team • 07/20/2019
The vulnerability identified as CVE-2003-0140 represents a critical buffer overflow flaw affecting the Mutt email client and its derivatives, specifically impacting versions 1.4.0 through 1.5.3 and earlier releases. This vulnerability stems from improper input validation within the IMAP folder handling mechanism, where the application fails to adequately check the length of folder names received from remote IMAP servers. The flaw manifests when malicious actors craft specially formatted folder names that exceed the allocated buffer space, leading to memory corruption that can result in application crashes or potentially arbitrary code execution. The vulnerability is particularly concerning because it operates at the network level, allowing remote attackers to exploit the flaw without requiring local system access or user interaction. This type of vulnerability falls under CWE-121, which describes heap-based buffer overflow conditions where insufficient boundary checking allows attackers to overwrite adjacent memory locations. The attack surface extends beyond just Mutt itself to include other email clients that utilize Mutt's underlying codebase such as Balsa email client, making the impact significantly broader than initially apparent.
The technical exploitation of this vulnerability occurs when an IMAP server responds to a folder listing request with a folder name that exceeds the predetermined buffer size allocated by the client application. When Mutt attempts to process this oversized folder name, the buffer overflow corrupts adjacent memory segments, potentially overwriting return addresses, function pointers, or other critical execution data. This memory corruption can cause the application to crash immediately, resulting in a denial of service condition that prevents legitimate users from accessing their email accounts. In more severe cases where the attacker can precisely control the overflowed memory content, the vulnerability may allow for arbitrary code execution, enabling malicious actors to gain unauthorized access to the victim's system. The exploitability of this vulnerability is enhanced by the fact that email clients typically operate in a privileged context and may have access to sensitive user data, making the potential impact of successful exploitation particularly severe.
The operational impact of CVE-2003-0140 extends beyond simple service disruption to encompass potential data compromise and system infiltration. Organizations relying on affected email clients face significant risks including email service outages, unauthorized access to sensitive communications, and potential escalation to full system compromise. The vulnerability's remote nature means that attackers can exploit it from anywhere on the internet without requiring physical access to target systems, making it particularly attractive for large-scale attacks. Security professionals must consider this vulnerability as part of a broader threat landscape where attackers may use it as a stepping stone to more sophisticated attacks. The flaw's presence in multiple applications that share common codebases means that the impact is not isolated to a single product but affects an entire ecosystem of email clients. This interconnectedness increases the complexity of remediation efforts and requires coordinated patching across multiple software products. The vulnerability also highlights the importance of input validation and memory safety practices in network-facing applications, particularly those handling user-supplied data from untrusted sources. Organizations should implement network segmentation and monitoring to detect potential exploitation attempts, while also ensuring that all affected applications are promptly updated to patched versions.
Mitigation strategies for CVE-2003-0140 should encompass both immediate defensive measures and long-term architectural improvements. The most effective immediate solution involves applying patches to all affected versions of Mutt and derivative applications, with particular attention to Balsa email client versions prior to 2.0.10. System administrators should implement network-level controls such as firewalls and email filtering systems to restrict access to potentially malicious IMAP servers and monitor for unusual folder listing patterns. Input validation should be enhanced at multiple levels including application-level checks, network-level filtering, and email server-side controls to prevent malformed folder names from reaching client applications. The vulnerability serves as a reminder of the critical importance of secure coding practices and the need for regular security assessments of email client applications. Organizations should also consider implementing intrusion detection systems that can identify patterns consistent with buffer overflow exploitation attempts, particularly those targeting IMAP protocols. Additionally, maintaining updated threat intelligence feeds and conducting regular vulnerability assessments will help identify similar vulnerabilities that may exist in other components of the email infrastructure. The remediation process should include comprehensive testing to ensure that patches do not introduce regressions in functionality while also validating that the fix effectively addresses the underlying buffer overflow condition. This vulnerability demonstrates the necessity of adopting defense-in-depth strategies that protect against multiple attack vectors and maintain robust security postures across all email client implementations.