CVE-2015-0563 in Wireshark
Summary
by MITRE
epan/dissectors/packet-smtp.c in the SMTP dissector in Wireshark 1.10.x before 1.10.12 and 1.12.x before 1.12.3 uses an incorrect length value for certain string-append operations, which allows remote attackers to cause a denial of service (application crash) via a crafted packet.
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Analysis
by VulDB Data Team • 03/02/2022
The vulnerability identified as CVE-2015-0563 affects the SMTP dissector component within Wireshark network protocol analyzer software. This issue exists in versions 1.10.x prior to 1.10.12 and 1.12.x prior to 1.12.3, representing a critical flaw in the application's packet parsing logic. The vulnerability stems from improper handling of string operations within the SMTP protocol dissection functionality, specifically when processing certain types of network packets that contain malformed SMTP data. The flaw manifests during the packet analysis phase where Wireshark attempts to dissect SMTP traffic for network monitoring and forensic analysis purposes. When encountering specially crafted packets that exploit this length calculation error, the application fails to properly manage memory allocation and string manipulation operations, leading to unpredictable behavior and potential application instability.
The technical root cause of this vulnerability can be classified as a buffer overflow condition or more specifically a heap-based buffer overflow, as documented in CWE-122. The flaw occurs in the packet-smtp.c file where string-append operations utilize incorrect length values, causing memory corruption during packet processing. When the SMTP dissector encounters malformed data within SMTP protocol packets, it attempts to append strings to internal buffers using improperly calculated lengths, which can result in writing beyond allocated memory boundaries. This type of error falls under the category of memory safety vulnerabilities and represents a classic example of improper input validation in network protocol parsing components. The incorrect length handling during string operations creates a condition where the application's memory management becomes compromised, leading to potential crashes or arbitrary code execution in extreme cases.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a significant security risk for network monitoring and forensic analysis environments. Network administrators and security professionals who rely on Wireshark for traffic analysis, incident response, and network troubleshooting could face complete application outages when processing maliciously crafted SMTP packets. The vulnerability allows remote attackers to craft specific network packets that trigger the flawed string-append logic, resulting in application crashes that disrupt network monitoring activities and potentially expose the monitoring infrastructure to further attacks. This type of vulnerability directly impacts the availability of network analysis services and can be exploited in various attack scenarios including network reconnaissance, where attackers might attempt to disrupt network monitoring systems or create conditions for more sophisticated attacks. The impact is particularly concerning in enterprise environments where network traffic analysis is critical for security operations and compliance monitoring.
Mitigation strategies for CVE-2015-0563 involve immediate patching of affected Wireshark installations to versions 1.10.12 or 1.12.3 and later, which contain the necessary fixes for the string-append operation length calculation. Network administrators should implement network segmentation and access controls to limit exposure to potentially malicious traffic, while also considering network monitoring solutions that can detect and filter suspicious SMTP traffic patterns. The vulnerability aligns with ATT&CK technique T1071.004 for application layer protocol: email protocols, highlighting the importance of proper input validation and memory management in network protocol analysis tools. Organizations should also implement regular security assessments and vulnerability scanning to identify similar issues in other network monitoring and analysis tools. Additionally, defensive measures including network intrusion detection systems that can identify malformed SMTP traffic patterns and application whitelisting controls can provide additional layers of protection against exploitation attempts. The fix implemented in the patched versions addresses the core memory management issue by correcting the length calculations used in string-append operations, ensuring proper memory boundaries are maintained during packet processing.