Attacker Value
Very High
(1 user assessed)
Exploitability
High
(1 user assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
2

CVE-2023-29357

Disclosure Date: June 14, 2023 •
CVE-2023-29357 CVSS v3 Base Score: 9.8
Exploited in the Wild
Reported by inokii
View Source Details
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

Microsoft SharePoint Server Elevation of Privilege Vulnerability

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1
Ratings
  • Attacker Value
    Very High
  • Exploitability
    High
CISA KEV ListedCommon in enterpriseEasy to weaponizeGives privileged accessUnauthenticatedVulnerable in default configuration
Technical Analysis

CVE-2023-29357 is a critical vulnerability in Microsoft SharePoint Server, classified as an Elevation of Privilege (EoP) flaw. . This vulnerability allows attackers to use spoofed JSON web tokens (JWTs) to gain Administrator privileges on the SharePoint host. The exploit does not require the attacker to have any privileges or for the user to perform any action​​​

The vulnerability was identified by Nguyễn Tiến Giang (Jang) of StarLabs SG and demonstrated at ZDI’s Pwn2Own hacking contest in March 2023. In September 2023, a technical writeup of the flaw and its use in a two-bug exploit chain to achieve pre-authentication remote code execution (RCE) on the SharePoint server was published, along with proof-of-concept (PoC) code demonstrating the attack​. Write-up link: https://starlabs.sg/blog/2023/09-sharepoint-pre-auth-rce-chain/

​​

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CVSS V3 Severity and Metrics
Base Score:
9.8 Critical
Impact Score:
5.9
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Microsoft SharePoint Server 2019 16.0.10399.20005
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • microsoft

Products

  • sharepoint server 2019

Exploited in the Wild

Reported by:

References

Canonical
CVE-2023-29357 (https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-29357)
Exploit
PoCs that have not been added by contributors directly have been sourced from: nomi-sec/PoC-in-GitHub.
A PoC added here by the AKB Worker must have at least 2 GitHub stars.
CVE-2023-29357 (https://github.com/Chocapikk/CVE-2023-29357) (Added by AKB Worker)
CVE-2023-29357-ExE (https://github.com/KeyStrOke95/CVE-2023-29357-ExE) (Added by AKB Worker)
Miscellaneous
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-29357

Additional Info

Authenticated
Unknown
Exploitable
Unknown
Reliability
Unknown
Stability
Unknown
Available Mitigations
Unknown
Shelf Life
Unknown
Userbase/Installbase
Unknown
Patch Effectiveness
Unknown
Technical Analysis