CVE-2005-0926 in Sylpheed
Summary
by MITRE
Buffer overflow in Sylpheed before 1.0.4 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via attachments with MIME-encoded file names.
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Analysis
by VulDB Data Team • 07/02/2019
The vulnerability identified as CVE-2005-0926 represents a critical buffer overflow flaw in the Sylpheed email client software prior to version 1.0.4. This security issue stems from inadequate input validation mechanisms within the application's handling of email attachments, specifically when processing MIME-encoded file names. The flaw manifests when the software encounters specially crafted email messages containing attachments with excessively long or malformed MIME-encoded filenames that exceed the allocated buffer space during processing. This particular vulnerability falls under the Common Weakness Enumeration category CWE-121, which classifies buffer overflow conditions where insufficient bounds checking allows attackers to write beyond allocated memory boundaries. The vulnerability presents a significant risk to users who receive email attachments from untrusted sources, as the buffer overflow can be exploited to cause unpredictable behavior in the application.
The technical exploitation of this vulnerability occurs when Sylpheed processes email messages containing attachments with maliciously constructed MIME-encoded filenames that trigger memory corruption during parsing operations. The buffer overflow conditions can lead to stack corruption or heap corruption depending on how the vulnerable code handles the input data, ultimately resulting in application crashes or potentially allowing remote code execution. Attackers can craft email messages with specially formatted attachment names that exceed the buffer limits, causing the program to overwrite adjacent memory locations. This type of vulnerability aligns with the MITRE ATT&CK framework's technique T1203, which covers exploitation for execution through buffer overflow attacks. The specific nature of the flaw suggests that the application fails to properly validate the length of decoded MIME-encoded filenames before copying them into fixed-size buffers, creating an opportunity for attackers to manipulate program execution flow.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can potentially enable remote code execution on affected systems. When an unsuspecting user opens an email with a maliciously crafted attachment, the Sylpheed client will attempt to parse and display the filename, triggering the buffer overflow condition. This can result in application crashes that prevent legitimate email processing, but more concerning is the potential for attackers to inject and execute arbitrary code within the context of the running email client. The vulnerability affects users who are actively using Sylpheed to process incoming email messages, particularly those who receive attachments from unknown senders or who have not applied the relevant security patches. The risk is compounded by the fact that email remains one of the primary attack vectors for malware distribution, making this vulnerability particularly dangerous in enterprise environments where email clients are frequently used.
Mitigation strategies for CVE-2005-0926 should focus on immediate patch deployment and implementation of defensive measures. Users and organizations should upgrade to Sylpheed version 1.0.4 or later, which contains the necessary fixes to address the buffer overflow conditions. Additionally, implementing email filtering mechanisms that scan for suspicious attachment patterns and length validation can provide additional layers of protection. Security administrators should consider disabling automatic attachment preview features in email clients to reduce the attack surface, as this functionality often triggers the vulnerable code paths. Network-level protections such as email gateway filtering and content inspection systems can help identify and block malicious email messages before they reach end-user systems. The vulnerability also underscores the importance of regular security updates and proper input validation practices in software development, particularly for applications that process untrusted data from external sources. Organizations should establish robust vulnerability management processes that ensure timely patch deployment and maintain awareness of known security issues affecting their email infrastructure.