Virtual Event Today: Supply Chain Security Summit - Join Event In-Progress

Security Experts:

Connect with us

Hi, what are you looking for?



Actively Exploited Windows Spoofing Flaw Patched Two Years After Disclosure

The actively exploited Windows spoofing vulnerability patched last week by Microsoft has been known for more than two years, researchers pointed out.

The actively exploited Windows spoofing vulnerability patched last week by Microsoft has been known for more than two years, researchers pointed out.

Microsoft’s August 2020 Patch Tuesday updates addressed 120 vulnerabilities, including an Internet Explorer zero-day that has been chained with a Windows flaw in attacks linked to the threat actor named DarkHotel, and a Windows spoofing issue tracked as CVE-2020-1464.

The tech giant describes CVE-2020-1464 as a spoofing flaw related to Windows incorrectly validating file signatures. An attacker can exploit the vulnerability to bypass security features and load improperly signed files, Microsoft says in its advisory.

Researchers analyzed CVE-2020-1464 after Microsoft released its patch and noticed that it’s likely a vulnerability that has been known for years and which Microsoft has been refusing to fix.

In a blog post published over the weekend, researcher Tal Be’ery explained that the vulnerability, which has been named GlueBall, has been known since August 2018, when a file sample exploiting it was uploaded to VirusTotal.

Microsoft was informed about the issue at the time and details were disclosed on the VirusTotal blog in January 2019, but the vendor decided not to fix it.

“Microsoft Windows keeps the Authenticode signature valid after appending any content to the end of Windows Installer (.MSI) files signed by any software developer. This behaviour can be exploited by attackers to bypass some security solutions that rely on Microsoft Windows code signing to decide if files are trusted. The scenario is especially dangerous when the appended code is a malicious JAR because the resulting file has a valid signature according to Microsoft Windows and the malware can be directly executed by Java,” Bernardo Quintero, founder of VirusTotal, explained in the January 2019 blog post.

Shortly after the blog post was published, several others analyzed the issue and made their findings public. In June 2020, researchers noticed that someone had been exploiting GlueBall to deliver malware, and in August it was finally patched by Microsoft.

“[The] way Microsoft had handled the vulnerability report seems rather strange,” Be’ery noted. “It was very clear to everyone involved, Microsoft included, that GlueBall is indeed a valid vulnerability exploited in the wild. Therefore, it is not clear why it was only patched now and not two years ago.”

SecurityWeek has reached out to Microsoft, but the company has not provided any clarifications regarding its decision not to patch CVE-2020-1464 sooner.

“A security update was released in August. Customers who apply the update, or have automatic updates enabled, will be protected. We continue to encourage customers to turn on automatic updates to help ensure they are protected,” said a Microsoft spokesperson.

Related: Windows Vulnerabilities Exploited for Code Execution, Privilege Escalation

Related: Windows and IE Zero-Day Vulnerabilities Chained in ‘PowerFall’ Attacks

Written By

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this webinar to learn best practices that organizations can use to improve both their resilience to new threats and their response times to incidents.


Join this live webinar as we explore the potential security threats that can arise when third parties are granted access to a sensitive data or systems.


Expert Insights

Related Content


Zendesk is informing customers about a data breach that started with an SMS phishing campaign targeting the company’s employees.


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...


The release of OpenAI’s ChatGPT in late 2022 has demonstrated the potential of AI for both good and bad.


Satellite TV giant Dish Network confirmed that a recent outage was the result of a cyberattack and admitted that data was stolen.


The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.

Application Security

PayPal is alerting roughly 35,000 individuals that their accounts have been targeted in a credential stuffing campaign.


No one combatting cybercrime knows everything, but everyone in the battle has some intelligence to contribute to the larger knowledge base.


A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...