Recent on-premises SharePoint Server vulnerabilities have exposed organizations to severe security risks, with attackers actively exploiting weaknesses in older SharePoint environments. These critical flaws allow unauthorized users to execute remote code, extract cryptographic keys, forge authentication tokens, and gain persistent access to sensitive SharePoint data. For businesses still running legacy SharePoint Server versions, the threat is immediate and significant, making prompt action essential.
These exploits have already affected hundreds of publicly exposed SharePoint servers, highlighting the growing urgency to secure on-premises environments. While SharePoint Online remains unaffected, older installations such as SharePoint Server 2019 or Subscription Edition become targets if not fully patched. This situation emphasizes how maintaining outdated systems without regular updates can open the door to large-scale data breaches.
To mitigate these SharePoint security vulnerabilities, administrators must apply Microsoft’s latest security patches, enable Antimalware Scan Interface (AMSI) in full mode, rotate their machine keys, and ensure that Defender Antivirus is actively scanning for malicious activity. Additionally, conducting thorough threat-hunting checks and investigating potential web shells are crucial steps in preventing further compromise.
These emerging threats make it clear that staying on legacy infrastructure is increasingly risky. Strengthening on-prem systems and considering a transition to SharePoint Online—where security updates are automated—can greatly reduce exposure. Organizations can rely on experienced partners like Apps4Rent for remediation, migration support, and long-term protection.