# CVE-2023-29357: Microsoft SharePoint Server 2019 - Privilege Escalation

> Live exploitation tracking for CVE-2023-29357 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2023-29357

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** Microsoft SharePoint Server 2019
- **Weaknesses:** CWE-303 (Incorrect Implementation of Authentication Algorithm)
- **Tags:** enterprise_software

## Description

Microsoft SharePoint Server Elevation of Privilege Vulnerability

## CrowdSec analysis

[CVE-2023-29357](https://euvd.enisa.europa.eu/vulnerability/CVE-2023-29357) is a critical privilege escalation vulnerability in Microsoft SharePoint Server 2019. This flaw could allow remote, unauthenticated attackers to gain elevated privileges on the affected SharePoint server, potentially leading to full system compromise and unauthorized access to sensitive data.

CrowdSec has been tracking this vulnerability and its exploits since 8th of April 2026.

CrowdSec has not observed any significant exploitation activity targeting CVE-2023-29357 across its network. As a result, no community-driven trend analysis is available for this vulnerability at this time.

Attackers exploit this vulnerability by sending forged JWT tokens with the "none" algorithm in the Authorization header to SharePoint API endpoints such as `/_api/web/siteusers`, bypassing authentication and gaining unauthorized access to sensitive SharePoint data.

## Timeline

- 2023-06-13: CVE Published. CVE-2023-29357 is published to NVD.
- 2024-01-10: CISA KEV. CVE-2023-29357 is added to the Known Exploited Vulnerabilities catalog by CISA.
- 2024-01-31: CISA Remediation Deadline. Expiration of the CISA remediation deadline as described in [BOD 22-01](https://www.cisa.gov/news-events/directives/bod-22-01-reducing-significant-risk-known-exploited-vulnerabilities).
- 2026-04-08: Rule Released. CrowdSec releases a rule to detect CVE-2023-29357 exploitation attempts against the CrowdSec Network.

## References

- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-29357
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-29357
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-29357.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2023-29357) follows observed exploitation activity for CVE-2023-29357. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.