CVE-2021-36321

Vulnerability

Dell Networking X-Series firmware versions prior to 3.0.1.9 (as well as Dell PowerEdge VRTX Switch Module firmware versions prior to 2.0.0.83) contain an improper input validation vulnerability in the affected code paths. The issue allows a remote unauthenticated attacker to send specially crafted data to the device, which can cause a denial of service [1]. The vulnerability is identified as CVE-2021-36321 with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) [1].

Exploitation

An attacker can exploit this vulnerability from a remote network position without any authentication or user interaction. The attacker sends specially crafted input to the vulnerable Dell device, taking advantage of the improper validation to trigger a crash or resource exhaustion [1]. According to the CVSS vector, the attack complexity is low, meaning no special conditions or race windows are required [1].

Impact

Successful exploitation results in a denial of service condition, impacting the availability of the affected switch. The confidentiality and integrity of the device remain unaffected, but the network service or the entire switch may become unresponsive until manually restored [1].

Mitigation

Dell has addressed this vulnerability in firmware version 3.0.1.9 for the Networking X-Series and version 2.0.0.83 for the Dell PowerEdge VRTX Switch Module. Users are advised to update to the latest firmware as referenced in DSA-2021-191 [1]. No workarounds have been published.