A critical zero-day vulnerability in on-premises SharePoint servers, CVE-2025-53770, has been actively exploited since July 7, affecting organizations worldwide. Despite patches from Microsoft, many systems remain vulnerable, leading to data theft and remote code execution risks. Curious about what this means for your organization? Below, we answer key questions about this serious cybersecurity threat and how to stay protected.
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What exactly is the SharePoint zero-day vulnerability CVE-2025-53770?
CVE-2025-53770 is a critical security flaw in on-premises SharePoint servers that allows hackers to execute remote code. Exploited since July 7, it involves attackers stealing cryptographic keys and using deserialization techniques to gain control over affected systems. This vulnerability is linked to previous SharePoint flaws and is being actively exploited by China-backed hacking groups targeting sensitive data.
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How are hackers exploiting SharePoint servers worldwide?
Hackers are exploiting CVE-2025-53770 by targeting vulnerable SharePoint servers across government agencies and private companies globally. They use stolen cryptographic keys and tools like ysoserial to generate malicious payloads, enabling remote code execution. Many organizations remain compromised despite Microsoft releasing patches, making them prime targets for data theft and espionage.
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What should organizations do now to protect their systems?
Organizations should immediately apply the latest patches released by Microsoft to fix the vulnerability. If patches are not yet available or systems are still vulnerable, disconnect affected servers from the network and monitor for suspicious activity. Security agencies like CISA and FBI recommend prioritizing patching and conducting thorough security audits to prevent further exploitation.
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Are there ongoing cyber threats related to this exploit?
Yes, the threat remains active, with hackers continuously exploiting the vulnerability to steal sensitive data and gain remote access. The attacks are sophisticated, often involving the theft of cryptographic keys and use of deserialization exploits. Organizations should stay vigilant, update their security measures, and watch for signs of ongoing or future attacks.
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How can I tell if my SharePoint server has been compromised?
Signs of compromise include unusual network activity, unexpected system behavior, or alerts from security tools indicating suspicious payloads or unauthorized access. If you suspect your SharePoint server is affected, consult cybersecurity experts immediately and review logs for any signs of exploitation or data theft.
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Will Microsoft release a permanent fix for this vulnerability?
Microsoft has issued emergency patches to address CVE-2025-53770. While these patches are designed to fix the vulnerability, organizations must ensure they are properly applied. Continued vigilance and regular updates are essential, as cybercriminals may develop new methods to exploit similar flaws in the future.