Advisory Details

July 19th, 2021

Microsoft SharePoint CabUtility ExtractCab Directory Traversal Remote Code Execution Vulnerability

ZDI-21-829
ZDI-CAN-13584

CVE ID CVE-2021-34468
CVSS SCORE 7.1, AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS SharePoint
VULNERABILITY DETAILS

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Microsoft SharePoint. User interaction is required to exploit this vulnerability.

The specific flaw exists within the parsing of CAB files. When handling filenames specified within a CAB file, the process does not properly validate a user-supplied path prior to using it in file operations. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the service account.

ADDITIONAL DETAILS Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://msrc.microsoft.com/update-guide/en-us/vulnerability/CVE-2021-34468
DISCLOSURE TIMELINE
  • 2021-05-07 - Vulnerability reported to vendor
  • 2021-07-19 - Coordinated public release of advisory
CREDIT Steven Seeley (mr_me) of Source Incite
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