CVE-2021-21510

Vulnerability

A host header injection vulnerability exists in Dell iDRAC8 versions prior to 2.75.100.75. The product does not properly validate or sanitize the Host header value in incoming HTTP requests, allowing an attacker to inject arbitrary Host header values. No special configuration or authentication is required to reach the vulnerable code path.

Exploitation

A remote unauthenticated attacker can exploit this vulnerability by sending a crafted HTTP request to an affected iDRAC8 instance with an arbitrary Host header value. The attacker does not require network position beyond being able to send network traffic to the iDRAC8 interface. User interaction is not required for the initial injection, but some impacts (such as cache poisoning) may require subsequent victim visits or interactions.

Impact

By injecting a manipulated Host header, the attacker can poison a web cache or trigger redirections. This corresponds to low impacts on confidentiality and integrity within an unchanged scope; the CVSS v3.1 vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N with a base score of 6.1 (Medium). An attacker cannot directly execute arbitrary code or elevate privileges, but can manipulate cached responses or redirect users to malicious sites.

Mitigation

Dell has released iDRAC8 firmware version 2.75.100.75 to address this vulnerability [1]. Customers should update to this version or later. No workaround is provided as a permanent fix; administrators should apply the update as soon as possible. The update can be downloaded from the Dell Support site [1].