Hackers Actively Attacking Microsoft SharePoint Vulnerability

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added a security flaw impacting Microsoft Sharepoint Server to its Known Exploited Vulnerabilities (KEV) catalog based on evidence of active exploitation in the wild.

The vulnerability, tracked as CVE-2023-24955 (CVSS score: 7.2), is a critical remote code execution flaw that allows an authenticated attacker with Site Owner privileges to execute arbitrary code.

“In a network-based attack, an authenticated attacker as a Site Owner could execute code remotely on the SharePoint Server,” Microsoft said in an advisory. The flaw was addressed by Microsoft as part of its Patch Tuesday updates for May 2023.

The development comes more than two months after CISA added CVE-2023-29357, a privilege escalation flaw in SharePoint Server, to its KEV catalog.

It’s worth pointing out that an exploit chain combining CVE-2023-29357 and CVE-2023-24955 was demonstrated by StarLabs SG at the Pwn2Own Vancouver hacking contest last year, earning the researchers a $100,000 prize.

That said, there is currently no information on the attacks weaponizing these two vulnerabilities and the threat actors that may be exploiting them.

Microsoft previously told The Hacker News that “customers who have enabled automatic updates and enable ‘Receive updates for other Microsoft products’ option within their Windows Update settings are already protected.”

Federal Civilian Executive Branch (FCEB) agencies are required to apply the fixes by April 16, 2024, to secure their networks against the active threat.