CVE-2015-8733 in Wireshark
Summary
by MITRE
The ngsniffer_process_record function in wiretap/ngsniffer.c in the Sniffer file parser in Wireshark 1.12.x before 1.12.9 and 2.0.x before 2.0.1 does not validate the relationships between record lengths and record header lengths, which allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted file.
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Analysis
by VulDB Data Team • 12/22/2024
The vulnerability identified as CVE-2015-8733 represents a critical memory safety issue within Wireshark's network protocol analysis tool, specifically affecting the ngsniffer_process_record function in the wiretap/ngsniffer.c component. This flaw exists in Wireshark versions 1.12.x prior to 1.12.9 and 2.0.x prior to 2.0.1, creating a significant risk for users who process potentially malicious network capture files. The vulnerability stems from insufficient validation mechanisms that fail to properly verify the relationship between record lengths and record header lengths, allowing attackers to craft specially malformed files that exploit this weakness.
The technical implementation of this vulnerability involves an out-of-bounds read condition that occurs when the ngsniffer_process_record function processes network capture files without adequate bounds checking. When a maliciously crafted file is loaded, the function attempts to access memory locations beyond the allocated buffer boundaries due to the lack of validation between header and record length fields. This improper validation creates a scenario where the application reads memory that it should not access, leading to unpredictable behavior and ultimately causing the application to crash. The flaw operates at the parsing layer of Wireshark's file processing pipeline, specifically targeting the Sniffer file format parser which handles various network capture formats.
From an operational perspective, this vulnerability presents a substantial denial of service risk that can be exploited remotely through crafted network capture files. Attackers can leverage this weakness by preparing specially formatted files that, when opened by Wireshark, trigger the out-of-bounds read condition and subsequent application crash. The impact extends beyond simple service disruption as this vulnerability can be weaponized in various attack scenarios including phishing campaigns where malicious files are distributed to unsuspecting users, or in penetration testing environments where the tool's reliability is crucial. The vulnerability's remote exploitability means that simply opening a malicious file within Wireshark's interface can compromise the system's availability.
Security practitioners should note that this vulnerability aligns with CWE-129, which describes improper validation of array indices, and can be mapped to ATT&CK technique T1059 for execution of malicious code through application manipulation. The flaw demonstrates poor input validation practices that are common in network analysis tools where complex file format parsing is required. Organizations using Wireshark for network monitoring, forensic analysis, or security research should prioritize immediate patching to mitigate this risk, as the vulnerability can be exploited without any user interaction beyond opening the malicious file. The patch released with Wireshark versions 1.12.9 and 2.0.1 addresses the core issue by implementing proper validation of record length relationships, ensuring that the application correctly validates header and record length fields before proceeding with memory access operations. This remediation follows industry best practices for preventing buffer overflow conditions and maintaining application stability during file processing operations.