Cisco NX-OS bash access control

Summaryinfo

A vulnerability, which was classified as critical, has been found in Cisco NX-OS. This affects an unknown function of the component bash. The manipulation leads to access control. This vulnerability is uniquely identified as CVE-2019-1596. Local access is required to approach this attack. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Cisco NX-OS (Router Operating System) (affected version unknown). This issue affects an unknown functionality of the component bash. The manipulation with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-264. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A vulnerability in the Bash shell implementation for Cisco NX-OS Software could allow an authenticated, local attacker to escalate their privilege level to root. The attacker must authenticate with valid user credentials. The vulnerability is due to incorrect permissions of a system executable. An attacker could exploit this vulnerability by authenticating to the device and entering a crafted command at the Bash prompt. A successful exploit could allow the attacker to escalate their privilege level to root. Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3500 Platform Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3600 Platform Switches are affected in versions prior to 7.0(3)F3(5). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected in versions prior to 7.0(3)I7(4). Nexus 9500 R-Series Line Cards and Fabric Modules are affected in versions prior to 7.0(3)F3(5).

The bug was discovered 03/06/2019. The weakness was disclosed 03/07/2019 as cisco-sa-20190306-nxos-pe as confirmed advisory (Website). It is possible to read the advisory at tools.cisco.com. The identification of this vulnerability is CVE-2019-1596 since 12/06/2018. Attacking locally is a requirement. The successful exploitation needs a simple authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

The vulnerability was handled as a non-public zero-day exploit for at least 1 days. During that time the estimated underground price was around $5k-$25k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 316380 (Cisco NX-OS Software Bash Shell Privilege Escalation Vulnerability(cisco-sa-20190306-nxos-pe)).

Upgrading eliminates this vulnerability.

The entry VDB-131450 is pretty similar. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• NX-OS

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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