Tenable Research Discovered a Download Hijack Vulnerability in Slack

Slack issues update but bad actors could have leveraged the flaw for corporate espionage or file manipulation

Tenable®, Inc., the Cyber Exposure company, today announced that its research team discovered a vulnerability in the Slack Desktop Application for Windows that could have allowed an attacker to alter where a victim’s files are stored when the documents are downloaded within Slack.

Slack has become a critical tool for many organizations looking to keep their employees connected. The vulnerability, which was found in Slack Desktop Application for Windows version 3.3.7 and has since been patched in version 3.4.0, could have allowed an attacker to send a crafted hyperlink via a Slack message that, once clicked, changes the document download location path to an attacker-owned file share. By exploiting the flaw, an attacker can not only steal future documents downloaded within Slack, but they can also manipulate them, such as injecting malicious code that would compromise the victim’s machine once opened.

“The digital economy and global distributed workforce have brought new technologies to market with the ultimate goal of seamless connectivity,” said Renaud Deraison, co-founder and chief technology officer, Tenable. “But it’s critical that organizations realize this emerging technology is potentially vulnerable and part of their expanding attack surface. Tenable Research continues to work with vendors such as Slack to disclose our discoveries to ensure consumers and organizations are secure.”

Slack has released version 3.4.0 to address this vulnerability. Users are urged to confirm that their Slack for Windows is updated to this latest version.

For more information on how this vulnerability was found, read the Tenable Research blog post on Medium.

About Tenable

Tenable®, Inc. is the Cyber Exposure company. Over 27,000 organizations around the globe rely on Tenable to understand and reduce cyber risk. As the creator of Nessus®, Tenable extended its expertise in vulnerabilities to deliver the world’s first platform to see and secure any digital asset on any computing platform. Tenable customers include more than 50 percent of the Fortune 500, more than 25 percent of the Global 2000 and large government agencies. Learn more at www.tenable.com.

Contact Information:

Cayla Baker
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