CVE-2023-29357
Published: January 10, 2024
Official Description
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.
CISA KEV Advisory
Microsoft SharePoint Server Privilege Escalation Vulnerability
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.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Risk Analysis
Microsoft SharePoint Server contains an unspecified vulnerability where an unauthenticated attacker can bypass authentication using spoofed JWT tokens to gain administrator privileges. The high EPSS score of 0.94356 indicates a very high likelihood of exploitation, and its presence in the KEV catalog confirms active exploitation.
This vulnerability is actively exploited in the wild. The flaw allows an unauthenticated attacker to gain administrator privileges by spoofing JWT authentication tokens.
Apply the latest security updates for Microsoft SharePoint Server to address this authentication bypass vulnerability. Implement robust token validation and review authentication mechanisms.
Technical Analysis
CVE-2023-29357 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2023-29357 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2023-29357 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1