CVE-2021-34468: Microsoft SharePoint CabUtility ExtractCab Directory Traversal Remote Code Execution Vulnerability
Microsoft SharePoint Server Remote Code Execution Vulnerability
Other sources
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.
— ZDI
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.5188.1000Patch KB5001976 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.0.5363.1000Patch KB5001992 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.10376.20001Patch KB5001975
Event History
Frequently Asked Questions
What is CVE-2021-34468?
CVE-2021-34468 is a vulnerability that allows network-adjacent attackers to execute arbitrary code on affected installations of Microsoft SharePoint.
How severe is CVE-2021-34468?
CVE-2021-34468 has a severity rating of high.
Which versions of Microsoft SharePoint are affected by CVE-2021-34468?
CVE-2021-34468 affects Microsoft SharePoint Foundation 2013 SP1, Microsoft SharePoint Server 2016, and Microsoft SharePoint Server 2019.
How can CVE-2021-34468 be exploited?
Exploiting CVE-2021-34468 requires user interaction and involves parsing of CAB files with specially crafted filenames.
Where can I find more information about CVE-2021-34468?
More information about CVE-2021-34468 can be found at the following references: [Microsoft Security Response Center](https://msrc.microsoft.com/update-guide/en-us/vulnerability/CVE-2021-34468), [Zero Day Initiative](https://www.zerodayinitiative.com/advisories/ZDI-21-829/), [Microsoft Security Guidance Advisory](https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34468).