Introduction

A critical deserialization vulnerability in Microsoft SharePoint [1] [5] [6], identified as CVE-2024-38094 [1] [2] [3] [7] [8], is actively being exploited and poses a significant threat to cybersecurity. This vulnerability affects multiple SharePoint products and allows attackers to execute arbitrary code, potentially leading to severe security breaches.

Description

A critical deserialization vulnerability in Microsoft SharePoint [1] [5] [6], tracked as CVE-2024-38094 [1] [2] [3] [7] [8], is currently under active exploit and serves as a frequent attack vector for malicious cyber actors. This high-severity flaw, which has a CVSS v4 score of 7.2 [4], affects multiple SharePoint products [5], including Microsoft SharePoint Server Subscription Edition [5], Microsoft SharePoint Server 2019 [4] [5] [6], and Microsoft SharePoint Enterprise Server 2016 [5]. It allows authenticated attackers with Site Owner permissions to inject and execute arbitrary code within the SharePoint environment due to an input validation error in the SharePoint Server Search component [7]. Alarmingly, an unauthenticated user can also exploit this vulnerability by sending a specially crafted HTTP request to the vulnerable SharePoint server [7], potentially enabling system takeover [7].

The Cybersecurity and Infrastructure Security Agency (CISA) has included CVE-2024-38094 in its Known Exploited Vulnerabilities (KEV) catalog [3] [4], underscoring the urgent need for remediation and highlighting its active exploitation in real-world scenarios. The risk of exploitation is heightened by the availability of publicly accessible proof-of-concept (PoC) exploits [2], which automate the process of authenticating to a SharePoint site and triggering the vulnerability [2]. This emphasizes the necessity for organizations to prioritize timely patching and implement security measures to mitigate risks, as exploitation can lead to serious consequences, including data breaches, ransomware attacks [5], and privilege escalation [5].

Patches addressing this security issue were released in July 2024 as part of Microsoft’s Patch Tuesday updates [2]. Federal Civilian Executive Branch (FCEB) agencies are mandated to apply the latest fixes by November 12, 2024 [1] [2] [4], to protect their networks from potential exploitation [2], as outlined in Binding Operational Directive (BOD) 22-01 [6], which emphasizes the need to mitigate risks from known exploited vulnerabilities [7]. Private organizations are also strongly encouraged to review the KEV catalog and address relevant vulnerabilities in their infrastructure to safeguard sensitive data and maintain operational security.

Conclusion

The exploitation of CVE-2024-38094 in Microsoft SharePoint underscores the critical need for organizations to remain vigilant and proactive in their cybersecurity efforts. Timely application of patches and adherence to security directives are essential to mitigate the risks associated with this vulnerability. As cyber threats continue to evolve, maintaining robust security measures and staying informed about potential vulnerabilities will be crucial in safeguarding sensitive information and ensuring operational integrity.

References

[1] https://www.darkreading.com/vulnerabilities-threats/microsoft-sharepoint-vuln-active-exploit
[2] https://thehackernews.com/2024/10/cisa-warns-of-active-exploitation-of.html
[3] https://thenimblenerd.com/article/sharepoint-security-snafu-cve-2024-38094-bug-bites-back/
[4] https://zerosecurity.org/cisa-adds-critical-microsoft-sharepoint-vulnerability-cve-2024-38094-known-exploited-vulnerabilities-catalog/14897/
[5] https://cyble.com/blog/cisa-warns-about-new-microsoft-sharepoint-vulnerability-cve-2024-38094/
[6] https://www.cisa.gov/news-events/alerts/2024/10/22/cisa-adds-one-known-exploited-vulnerability-catalog
[7] https://securityaffairs.com/170157/security/u-s-cisa-adds-microsoft-sharepoint-flaw-known-exploited-vulnerabilities-catalog.html
[8] https://thenimblenerd.com/article/microsoft-sharepoint-flaw-a-comedy-of-exploits-and-urgent-patches/