CVE-2019-1836
A vulnerability in the system shell for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an authenticated, local attacker to use symbolic links to overwrite system files.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A vulnerability in the system shell for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an authenticated, local attacker to use symbolic links to overwrite system files. These system files may be sensitive and should not be overwritable by non-root users. The attacker would need valid device credentials. The vulnerability is due to incorrect symbolic link verification of directory paths when they are used in the system shell. An attacker could exploit this vulnerability by authenticating to the device and providing crafted user input to specific symbolic link CLI commands. Successful exploitation could allow the attacker to overwrite system files that should be restricted. This vulnerability has been fixed in software version 14.1(1i).
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
- EPSS
- 0.44% probability · 37th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-22, CWE-59
- Affected
- cisco/nx-os
- Source
- psirt@cisco.com
References
- http://www.securityfocus.com/bid/108150Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-fabric-traversalVendor Advisory
- http://www.securityfocus.com/bid/108150Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-fabric-traversalVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.