CVE-2026-76926 in BUSMASTER
Summary
by MITRE • 08/20/2026
BUSMASTER file parser abnormal exit in 4.6.0 to 4.6.7 and 4.4.0 to 4.4.18 allows denial of service
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified involves a critical flaw within the BUSMASTER software, specifically affecting versions ranging from 4.4.0 through 4.4.18 and 4.6.0 through 4.6.7. This issue centers on an abnormal exit condition triggered during the parsing of specific input files formatted for CAN bus analysis. As a specialized tool used extensively in automotive embedded systems development, BUSMASTER is designed to read, write, and analyze data from Controller Area Network buses. The parser component responsible for interpreting these file formats contains a logic error or memory management flaw that fails to handle certain malformed or unexpectedly structured inputs gracefully. When an attacker provides a crafted input file containing specific sequences of bytes or structural anomalies, the application does not validate the integrity of the data prior to processing it in a manner that leads to a crash rather than returning an appropriate error code or continuing operation safely.
From a technical perspective, this vulnerability is classified as a denial-of-service condition resulting from improper exception handling and input validation failures. The root cause aligns with Common Weakness Enumeration categories such as CWE-20 Improper Input Validation and potentially CWE-787 Out-of-bounds Write if the crash involves memory corruption leading to an access violation, though the primary observable effect is application termination. In many cases of this nature in C or C++ based applications like BUSMASTER, the abnormal exit may stem from a null pointer dereference, buffer overflow, or heap corruption that triggers an unhandled exception within the operating system's runtime environment. The parser likely attempts to access memory addresses that are invalid due to incorrect length calculations derived from maliciously crafted file headers or payload data structures. This lack of robust boundary checking allows external actors to force the application into a fatal error state, effectively rendering it unusable until restarted.
The operational impact of this vulnerability is significant for organizations relying on BUSMASTER for continuous integration testing, automated regression suites, or manual diagnostic workflows in automotive engineering environments. A denial-of-service attack against such tools disrupts development cycles and can lead to data loss if unsaved work is present at the time of the crash. Furthermore, because these files are often exchanged between team members via email or shared network drives, a malicious actor could distribute a poisoned file that triggers this flaw upon opening by any engineer using an affected version of the software. This creates a vector for targeted disruption within development teams, potentially delaying project timelines and increasing operational costs due to downtime and recovery efforts. In more severe scenarios where the crash leads to memory corruption, there may be secondary risks involving code execution if the attacker can control the overwritten data structures, although the primary reported impact remains service interruption.
Mitigation strategies for this vulnerability primarily involve immediate software updates provided by the vendor. Organizations should upgrade BUSMASTER to versions released after 4.6.7 and 4.4.18 where these parsing flaws have been corrected with proper input sanitization and exception handling routines. Until an update can be applied, administrators should implement strict file intake policies that restrict the types of files allowed into development environments or utilize sandboxing techniques to isolate the application from untrusted inputs. Additionally, integrating static analysis tools during the build process for internal modifications and employing dynamic fuzzing testing on custom parsers can help identify similar weaknesses before deployment. Security awareness training for engineering staff regarding the risks of opening unsolicited CAN database files is also recommended to reduce the likelihood of successful exploitation through social engineering tactics that align with ATT&CK techniques such as T1566 Phishing or T1059 Command and Scripting Interpreter if used in conjunction with other malware delivery methods.