CVE-2013-2481 in Wireshark
Summary
by MITRE
Integer signedness error in the dissect_mount_dirpath_call function in epan/dissectors/packet-mount.c in the Mount dissector in Wireshark 1.6.x before 1.6.14 and 1.8.x before 1.8.6, when nfs_file_name_snooping is enabled, allows remote attackers to cause a denial of service (application crash) via a negative length value.
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Analysis
by VulDB Data Team • 05/06/2021
The vulnerability identified as CVE-2013-2481 represents a critical integer signedness error within Wireshark's Mount protocol dissector implementation. This flaw exists in the dissect_mount_dirpath_call function located in epan/dissectors/packet-mount.c, affecting versions 1.6.x prior to 1.6.14 and 1.8.x prior to 1.8.6. The vulnerability manifests when the nfs_file_name_snooping feature is enabled, creating a condition where remote attackers can manipulate packet data to trigger application instability. The flaw stems from improper handling of signed integer values during packet parsing operations, specifically when processing directory path information in NFS (Network File System) mount requests. This type of vulnerability falls under CWE-191, which specifically addresses integer underflow conditions, and represents a classic example of improper input validation in network protocol analysis tools.
The technical exploitation of this vulnerability occurs when a malicious attacker crafts a specially formatted network packet containing a negative length value within the mount directory path data structure. When Wireshark's dissector processes this malformed data, the negative signed integer value causes unexpected behavior in the application's memory management and packet parsing logic. The signedness error leads to a scenario where the application attempts to allocate memory or process data structures using a negative value as a size parameter, resulting in memory corruption or invalid memory access patterns. This typically manifests as an application crash or denial of service condition, effectively preventing legitimate network analysis operations from continuing. The vulnerability demonstrates the dangerous consequences of not properly validating input parameters in protocol dissectors, as these components are responsible for interpreting and displaying network traffic data.
From an operational impact perspective, this vulnerability significantly affects network security professionals and analysts who rely on Wireshark for network monitoring and troubleshooting. The denial of service condition can disrupt critical network analysis activities, potentially causing analysts to lose visibility into network traffic during important investigations or security incidents. The vulnerability is particularly concerning in environments where automated network monitoring systems depend on continuous Wireshark operation, as a successful attack could lead to complete loss of network traffic analysis capabilities. Additionally, the vulnerability's remote exploitation capability means that attackers need not be physically present on the network, making it a significant threat to organizations that use Wireshark for security monitoring. The attack vector through network packet manipulation aligns with ATT&CK technique T1046, which involves network service scanning and protocol manipulation, and represents a form of protocol-based attack that targets application-level vulnerabilities rather than network infrastructure weaknesses.
Mitigation strategies for CVE-2013-2481 primarily focus on immediate version updates to patched releases of Wireshark, specifically upgrading to version 1.6.14 or 1.8.6 and later. Network administrators should also consider implementing network segmentation and access controls to limit exposure of systems running Wireshark to untrusted network traffic. The vulnerability highlights the importance of input validation in protocol dissector implementations, with recommended practices including comprehensive parameter validation, proper integer range checking, and implementation of defensive programming techniques. Organizations should also consider disabling unnecessary features such as nfs_file_name_snooping when not required for specific analysis tasks, as this reduces the attack surface. The vulnerability serves as a reminder of the critical need for thorough testing of protocol dissector components, particularly in security tools that process untrusted network data, and demonstrates the importance of maintaining up-to-date security software to protect against known vulnerabilities.