A recently uncovered vulnerability in Google Drive presents a significant risk, potentially allowing cybercriminals to distribute malware disguised as legitimate files. This largely unaddressed security oversight enables attackers to leverage Google Drive’s file version management feature, resulting in higher success rates for spear-phishing schemes.
The flaw, which Google is reportedly aware of but has not yet fixed, lies within the “manage versions” functionality of Google Drive. This feature is designed to allow users to upload updated versions of existing documents. However, the mechanism fails to enforce file extension validation, allowing malicious actors to upload harmful executable files while retaining the appearance of legitimate documents.
According to system administrator A. Nikoci, who reported the vulnerability and later shared details with The Hacker News, attackers can upload new file versions with any extension to existing files in cloud storage. This creates an opportunity for deceiving users; shared documents can be replaced with malware-laden files that appear unchanged when previewed online, only revealing their malicious nature upon download.
Nikoci emphasized the lack of checks on file types within the version management tool, stating, “Google lets you change the file version without checking if it’s the same type.” This oversight poses a serious risk, as attackers can utilize the trusted nature of cloud services like Google Drive to mount highly effective spear-phishing campaigns.
While there is no evidence yet that this vulnerability has been exploited in practice, it mirrors previous incidents where cloud services become channels for malware delivery. For example, Zscaler reported earlier this year on phishing campaigns where Google Drive was used to distribute password-stealing malware.
Spear-phishing tactics often involve tricking users into opening malicious attachments or links, ultimately leading to compromised credentials or access to personal information. As such, this recent vulnerability could serve as a springboard for whaling attacks, where cybercriminals impersonate upper management to target specific individuals within organizations.
Additionally, Google Chrome’s apparent trust in files sourced from Google Drive, even when flagged by antivirus software as harmful, exacerbates the risk. Users are likely to download updates to shared files without second-guessing their safety, thereby increasing the likelihood of infection through malware.
Given the increasing reliance on cloud services for collaboration, it is essential that organizations closely monitor shared file notifications. The potential for such vulnerabilities to be exploited underscores the necessity for robust security practices to mitigate risk, particularly in the context of cloud-based platforms that have been proven to deliver malware.
As organizations continue to navigate this landscape, understanding the impact of tactics outlined in the MITRE ATT&CK Framework—such as initial access, execution, and persistence—can be instrumental in enhancing their defense strategies against evolving cyber threats. The emergence of this flaw serves as a reminder for business owners to remain vigilant, ensuring that both technical solutions and employee training align to protect against these emerging threats.
