CVE-2014-4020 in Wireshark
Summary
by MITRE
The dissect_frame function in epan/dissectors/packet-frame.c in the frame metadissector in Wireshark 1.10.x before 1.10.8 interprets a negative integer as a length value even though it was intended to represent an error condition, which allows remote attackers to cause a denial of service (application crash) via a crafted packet.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/22/2021
The vulnerability identified as CVE-2014-4020 resides within the frame metadissector component of Wireshark, specifically in the dissect_frame function located in epan/dissectors/packet-frame.c. This issue affects Wireshark versions 1.10.x prior to 1.10.8, representing a critical flaw in the network protocol analysis tool's packet processing logic. The vulnerability stems from an improper handling of integer values during packet dissection, where negative integers that should indicate error conditions are being interpreted as valid length parameters. This misinterpretation occurs within the context of packet metadata processing, which is essential for Wireshark's ability to analyze network traffic and extract meaningful information from captured packets.
The technical flaw manifests when the dissect_frame function encounters a negative integer value that was originally intended to represent an error condition or invalid state. Instead of properly handling this negative value as an error indicator, the function proceeds to use it as a length parameter for processing subsequent packet data. This erroneous interpretation causes the application to attempt operations with invalid memory addresses or buffer sizes, leading to unpredictable behavior and ultimately resulting in application crashes. The vulnerability represents a classic case of improper input validation and error handling, where the software fails to distinguish between legitimate data values and error indicators, creating a path for malicious input to trigger system instability.
The operational impact of this vulnerability is significant, as it enables remote attackers to execute a denial of service attack against Wireshark installations. An attacker can craft a specially designed packet that, when processed by the vulnerable Wireshark version, will trigger the application crash. This makes the vulnerability particularly dangerous in network monitoring environments where Wireshark is used to analyze traffic from potentially hostile sources. The attack requires no special privileges or authentication, making it accessible to anyone capable of sending network packets to a target system running the vulnerable software. The vulnerability essentially allows an attacker to remotely disrupt network analysis operations, potentially preventing security professionals from monitoring or investigating network traffic during critical incidents.
This vulnerability aligns with CWE-191, which describes integer underflow or wraparound conditions, and more specifically relates to improper handling of error codes within integer operations. The flaw also maps to ATT&CK technique T1499.004, which covers network denial of service attacks through manipulation of network protocols. From a defensive perspective, the recommended mitigation involves upgrading to Wireshark version 1.10.8 or later, which contains the necessary patches to properly handle negative integer values as error conditions rather than length parameters. Additionally, network administrators should implement proper input validation and sanitization practices when processing network traffic, and consider deploying intrusion detection systems that can identify and block malformed packets targeting known vulnerabilities in network analysis tools. The incident underscores the importance of robust error handling in security tools, where improper handling of edge cases can lead to complete system compromise through denial of service attacks.