CVE-2023-4875 in Mutt
Summary
by MITRE • 09/09/2023
Null pointer dereference when composing from a specially crafted draft message in Mutt >1.5.2 <2.2.12
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/08/2025
The vulnerability identified as CVE-2023-4875 represents a critical null pointer dereference flaw within the Mutt email client software. This issue affects versions greater than 1.5.2 and less than 2.2.12, creating a potential avenue for remote code execution or denial of service attacks. The vulnerability manifests specifically during the composition process when handling specially crafted draft messages, indicating a fundamental flaw in input validation and memory management within the email client's message handling subsystem. The flaw occurs when the application attempts to dereference a null pointer while processing malformed draft content, leading to unpredictable behavior and system instability.
The technical nature of this vulnerability aligns with CWE-476, which specifically addresses null pointer dereference conditions in software applications. This weakness occurs when an application fails to properly validate pointer values before attempting to access memory locations referenced by those pointers. In the context of Mutt's composition functionality, the application appears to lack adequate safeguards against malformed draft messages that could contain null references or improperly structured data. The flaw likely stems from insufficient input sanitization during the parsing of draft message content, particularly when handling attachments, headers, or message formatting elements that may contain crafted malicious data.
Operationally, this vulnerability presents significant risks to users who regularly compose and manage email drafts, as attackers could potentially craft malicious draft messages that trigger the null pointer dereference when the user attempts to open or process these drafts. The impact extends beyond simple application crashes to potentially enable more sophisticated attacks including remote code execution, especially if the application's memory corruption can be exploited through controlled input manipulation. Given that Mutt is widely used in both personal and enterprise email environments, this vulnerability could affect numerous users and organizations that rely on the software for email management. The vulnerability's exploitation potential increases when considering that draft messages are often stored locally and may be accessed by multiple users or automated processes.
Mitigation strategies for this vulnerability should prioritize immediate patching to versions 2.2.12 or later where the null pointer dereference has been addressed through proper input validation and memory management controls. System administrators should implement proactive monitoring for any suspicious draft message handling activities and consider restricting the import of external draft messages from untrusted sources. Additionally, implementing application sandboxing techniques and enhanced input validation routines can help prevent exploitation attempts. The vulnerability's classification under ATT&CK technique T1203 - Exploitation for Client Execution suggests that organizations should strengthen their endpoint protection measures and consider implementing network segmentation to limit potential lateral movement if exploitation occurs. Organizations should also conduct thorough security assessments of their email environments to identify any other applications or systems that might be similarly vulnerable to null pointer dereference attacks.