Microsoft’s latest security updates patch more wormable vulnerabilities related to Remote Desktop Services (RDS) and the company has published a blog post to warn users about the risk they pose.
Microsoft’s August 2019 Patch Tuesday updates fix over 90 flaws, including some critical RDS vulnerabilities that can be exploited by sending specially crafted requests to the targeted system via RDP. Exploitation of the vulnerabilities does not require any user interaction or authentication.
“These two vulnerabilities are also ‘wormable’, meaning that any future malware that exploits these could propagate from vulnerable computer to vulnerable computer without user interaction,” said Simon Pope, Director of Incident Response at MSRC.
However, experts have pointed out that two other RDS flaws resolved this month, CVE-2019-1222 and CVE-2019-1226, also have a very similar description and are also more likely to be exploited in malicious attacks.
CVE-2019-1181 and CVE-2019-1182 appear to impact all supported versions of Windows, while CVE-2019-1222 and CVE-2019-1226 only affect Windows 10, Windows Server, and Windows Server 2019.
Users can partially mitigate these types of vulnerabilities by enabling Network Level Authentication (NLA). This method only works as long as the attacker doesn’t find a way to obtain valid credentials.
Microsoft has issued several warnings about the BlueKeep vulnerability. The company’s most recent blog post on the matter, published on August 8, informed users that there were still more than 400,000 endpoints vulnerable to attacks due to the lack of NLA.
In a report published recently, cybersecurity firm BitSight said it had seen over 788,000 systems that were still vulnerable to BlueKeep attacks as of July 23.
While several companies and researchers claim to have developed proof-of-concept (PoC) exploits for the BlueKeep vulnerability, attacks have yet to be seen in the wild. However, many, including Microsoft, believe it’s only a matter of time until we see malicious attacks. Others have pointed out that BlueKeep may have already been exploited in targeted attacks that have not been made public.