Overview
The cybersecurity world is yet again faced with a significant vulnerability, CVE-2023-35995, which is threatening to compromise the integrity of systems globally. This vulnerability affects the GTKWave 3.3.115, an open-source waveform viewer which is extensively used across various industries for debugging and verification of digital circuits. The cause of concern is the possibility of arbitrary code execution, which can lead to a system compromise or data leakage. This underscores the importance of understanding and mitigating this vulnerability as it can be exploited by malicious actors to gain unauthorized access to sensitive data.
Vulnerability Summary
CVE ID: CVE-2023-35995
Severity: High (7.8 CVSS Score)
Attack Vector: Local
Privileges Required: Low
User Interaction: Required
Impact: System compromise, potential data leakage
Affected Products
No phone number, email, or personal info required.
Product | Affected Versions
GTKWave | 3.3.115
How the Exploit Works
The vulnerability stems from multiple improper array index validations in the fstReaderIterBlocks2 tdelta functionality of GTKWave 3.3.115. A malicious actor can exploit this by creating a specially crafted .fst file, leading to arbitrary code execution. A victim would need to open this malicious file to trigger the vulnerability. More specifically, this vulnerability concerns the tdelta indexing when signal_lens is 1, which is not adequately validated, opening up a potential gateway for arbitrary code execution.
Conceptual Example Code
Below is a conceptual example of how the vulnerability might be exploited. This pseudocode represents the crafting of a malicious .fst file:
def create_malicious_fst():
# Initialize malicious fst file
fst_file = FstFile("malicious.fst")
# Set signal_lens to 1 to exploit vulnerability
fst_file.set_signal_lens(1)
# Insert malicious code that will be executed upon opening the file
fst_file.insert_code("malicious_code")
# Save the fst file
fst_file.save()The above pseudocode outlines the potential steps a malicious actor could take to exploit the vulnerability. They craft a malicious .fst file and set signal_lens to 1, exploiting the improper array index validation. They then insert malicious code that would be executed when the target opens the file.
How to Mitigate
The best mitigation strategy currently available is to apply the vendor patch. If the patch cannot be applied immediately, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as a temporary mitigation measure. However, it is highly recommended to apply the vendor patch as soon as possible to ensure the security of your systems.