Microsoft SharePoint Server Privilege Escalation Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2024-01-10
• Known to be used in ransomware campaigns
• EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official description

Microsoft SharePoint Server Elevation of Privilege Vulnerability

CISA: Microsoft SharePoint Server contains an unspecified vulnerability that allows an unauthenticated attacker, who has gained access to spoofed JWT authentication tokens, to use them for executing a network attack. This attack bypasses authentication, enabling the attacker to gain administrator privileges.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 31 Jan 2024): Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

• Patch on msrc.microsoft.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ References ]References

• msrc.microsoft.com/update-guide/vulnerability/CVE-2023-29357PatchVendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource