Researchers Uncover Publisher Spoofing Bug in Microsoft Visual Studio Installer


Jun 12, 2023Ravie LakshmananVulnerability / Software

Security researchers have warned about an “easily exploitable” flaw in the Microsoft Visual Studio installer that could be abused by a malicious actor to impersonate a legitimate publisher and distribute malicious extensions.

“A threat actor could impersonate a popular publisher and issue a malicious extension to compromise a targeted system,” Varonis researcher Dolev Taler said. “Malicious extensions have been used to steal sensitive information, silently access and change code, or take full control of a system.”

The vulnerability, which is tracked as CVE-2023-28299 (CVSS score: 5.5), was addressed by Microsoft as part of its Patch Tuesday updates for April 2023, describing it as a spoofing flaw.


The bug discovered by Varonis has to do with the Visual Studio user interface, which allows for spoofed publisher digital signatures.

Specifically, it trivially bypasses a restriction that prevents users from entering information in the “product name” extension property by opening a Visual Studio Extension (VSIX) package as a .ZIP file and then manually adding newline characters to the “DisplayName” tag in the “extension.vsixmanifest” file.

Microsoft Visual Studio

By introducing enough newline characters in the vsixmanifest file and adding fake “Digital Signature” text, it was found that warnings about the extension not being digitally signed could be easily suppressed, thereby tricking a developer into installing it.


🔐 Mastering API Security: Understanding Your True Attack Surface

Discover the untapped vulnerabilities in your API ecosystem and take proactive steps towards ironclad security. Join our insightful webinar!

Join the Session

In a hypothetical attack scenario, a bad actor could send a phishing email bearing the spoofed VSIX extension by camouflaging it as a legitimate software update and, post-installation, gain a foothold into the targeted machine.

The unauthorized access could then be used as a launchpad to gain deeper control of the network and facilitate the theft of sensitive information.

“The low complexity and privileges required make this exploit easy to weaponize,” Taler said. “Threat actors could use this vulnerability to issue spoofed malicious extensions with the intention of compromising systems.”

Found this article interesting? Follow us on Twitter and LinkedIn to read more exclusive content we post.

Products You May Like

Articles You May Like

Rhadamanthys Malware Deployed By TA547 Against German Targets
Google Chrome Adds V8 Sandbox – A New Defense Against Browser Attacks
Hackers Use Malware to Hunt Software Vulnerabilities
Popular Rust Crate liblzma-sys Compromised with XZ Utils Backdoor Files
CISO Perspectives on Complying with Cybersecurity Regulations

Leave a Reply

Your email address will not be published. Required fields are marked *