CVE-2025-53770
NVD has not published a description yet.
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CISA says: Disconnect public-facing versions of SharePoint Server that have reached their end-of-life (EOL) or end-of-service (EOS) to include SharePoint Server 2013 and earlier versions. For supported versions, please follow the mitigations according to CISA (URL listed below in Notes) and vendor instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.
Show me how to fix itTimeline
- Added to CISA known exploited list
- First covered by RedTeamDaily
Coverage
Storm-2603 used ToolShell SharePoint flaws in a fileless intrusion over Christmas
Storm-2603 exploited CVE-2025-53770 and CVE-2025-53771 (ToolShell) in on-premises SharePoint to achieve remote code execution. The attacker ran a webshell inside the IIS worker process (w3wp.exe) that stayed memory-resident, after an initial probe on 20 December and a full exploitation on 24 December. The first probe was initially rated low priority and only linked to the intrusion retrospectively.
Sources: NVD and CISA known exploited vulnerabilities catalogue.