CVE-2012-0042 in Wireshark
Summary
by MITRE
Wireshark 1.4.x before 1.4.11 and 1.6.x before 1.6.5 does not properly perform certain string conversions, which allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted packet, related to epan/to_str.c.
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Analysis
by VulDB Data Team • 03/20/2021
The vulnerability identified as CVE-2012-0042 represents a critical denial of service flaw in Wireshark network protocol analyzer versions 1.4.x prior to 1.4.11 and 1.6.x prior to 1.6.5. This issue stems from improper string conversion handling within the application's core functionality, specifically within the epan/to_str.c module that manages string representations of various protocol elements. The flaw manifests when Wireshark processes specially crafted network packets that contain malformed string data, leading to unpredictable application behavior and system instability.
The technical root cause of this vulnerability lies in the insufficient input validation and string handling mechanisms within Wireshark's protocol decoding engine. When processing network traffic, the application attempts to convert certain protocol values into human-readable string representations, but fails to properly validate the input data before performing these conversions. This inadequate validation results in a NULL pointer dereference condition that occurs during the string conversion process in the to_str.c file. The vulnerability is classified under CWE-476 as a NULL Pointer Dereference, which represents a common software flaw where an application attempts to access memory through a null pointer reference, leading to application crashes and potential system instability.
From an operational perspective, this vulnerability presents a significant risk to network monitoring and security analysis operations. Remote attackers can exploit this flaw by crafting malicious network packets designed to trigger the NULL pointer dereference condition when processed by vulnerable Wireshark installations. The impact extends beyond simple application crashes to potentially disrupt network monitoring activities, as security analysts and network administrators rely heavily on Wireshark for traffic analysis and incident response. The vulnerability's remote exploitability means that attackers do not require local access to the system, making it particularly dangerous in networked environments where Wireshark might be deployed for network traffic inspection.
The attack vector for this vulnerability is particularly concerning as it can be triggered through normal network traffic processing without requiring any special privileges or authentication. When a vulnerable Wireshark instance processes a malicious packet, the application crashes and terminates unexpectedly, effectively causing a denial of service for the monitoring system. This disruption can have cascading effects on network security operations, potentially masking actual network threats while the monitoring system is offline. The vulnerability aligns with ATT&CK technique T1499.004 for network denial of service attacks, as it specifically targets the availability of network monitoring tools through application-level exploitation.
Organizations using affected Wireshark versions should immediately implement mitigations including updating to the patched versions 1.4.11 and 1.6.5, which contain proper input validation and string handling routines. Network administrators should also consider implementing additional monitoring and alerting mechanisms to detect application crashes and ensure rapid response to potential exploitation attempts. The fix addresses the underlying NULL pointer dereference by implementing proper bounds checking and input validation before string conversion operations, preventing the application from attempting to dereference null pointers during protocol analysis. Additionally, organizations should review their network monitoring strategies to ensure redundancy and alternative analysis tools are available in case of primary monitoring system failures.