Cisco UCS Director CopyFileRunnable run Symlink Following Remote Code Execution Vulnerability

April 16th, 2020
ZDI-20-541 ZDI-CAN-9593

CVE ID

CVE-2020-3247

CVSS Score

9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors

Cisco

Affected Products

UCS Director

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Cisco UCS Director. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the processing of tar files by the LargeFileUploadServlet endpoint. The issue results from the lack of proper validation of a user-supplied UNIX symbolic link prior to using it in file operations. An attacker can leverage this vulnerability to execute code in the context of the tomcat service.

Additional Details

Cisco has issued an update to correct this vulnerability. More details can be found at:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucsd-mult-vulns-UNfpdW4E

Disclosure Timeline

  • 2019-12-20 - Vulnerability reported to vendor
  • 2020-04-16 - Coordinated public release of advisory

Credit

Steven Seeley (mr_me) of Source Incite

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