In early 2022, Intel released security advisories revealing a flaw found in older versions of the Intel(R) Server Platform Services (SPS) firmware. Tracked as CVE-2022-29466, this vulnerability made it possible for an authenticated user, with local access to the device, to trigger a denial of service. Below, we'll break down what this means, provide context with simple code examples, offer advice to users, and point you to original sources. This deep dive is written with clarity to help both seasoned admins and learning enthusiasts.

What is Intel(R) SPS?

Intel(R) Server Platform Services, or SPS, is a type of embedded firmware technology that manages various platform-level tasks, including security, power management, and remote administration. SPS is commonly deployed in enterprise servers, especially in data centers using Intel’s Xeon processors.

Intel described this vulnerability as

> Improper input validation in the firmware for Intel(R) SPS before version SPS_E3_04.01.04.700. may allow an authenticated user to potentially enable denial of service via local access. (Source: Intel Security Advisory, INTEL-SA-00702)

The SPS firmware doesn't thoroughly check (validate) some input it receives.

- If a logged-in user crafts their input a certain way, it could crash or freeze the entire server — making it unavailable for everyone else.
- This can only be exploited from local access (someone already logged in, like a technician or an attacker who gained credentials).

Simple Example: How Input Validation Could Fail

Suppose the firmware expects a specific setting to be within a numbered range (say, 1 to 10). If no one checks that the value is valid, it could cause problems:

// Pseudo-code, similar to what embedded firmware might use:
void set_config(int input_value) {
    // Lack of proper input validation!
    config_setting = input_value;
    apply_settings(config_setting); // This might crash if input_value is crazy
}

Here, if set_config(-99999) was called, apply_settings() could fail terribly, leading to a crash. In the context of SPS, such a crash would take down hardware monitoring, power management, and remote management, halting server operations.

Exploitation Details

*Intel has not shared full technical exploit code, but based on advisory info, here’s what an exploit scenario might look like:*

Prerequisite: The attacker must be logged in (they’re an authenticated user).

- Action: The attacker runs a (possibly proprietary) tool or command utility available on the server that communicates with the SPS firmware.
- Exploit: They send a specifically malformed input — like out-of-range data, excessively long strings, or special character sequences — that causes SPS to choke.
- Result: The SPS management engine halts, potentially taking down server monitoring and management features. In worst cases, it can force a server reboot or lockup, making it unavailable — a denial of service.

A hypothetical PoC (proof-of-concept) might look like

# This hypothetical tool interacts with SPS (not publicly available)
sps_set_parameter --parameter="power_state" --value="INVALID_VALUE"

*The above, if unchecked by validation, could trigger firmware errors.*

Real-World Impact

- Sensitive Environments: In data centers with multi-user environments, if an attacker already has a user account, they could weaponize this bug to bring servers down.
- Availability at Risk: While remote exploitation isn’t possible, the bug could help a malicious insider disrupt services.
- Severity: Intel marked the base CVSS score as “Medium” — it's not easy to exploit, but the impact can be significant.

Mitigation & Recommendations

- Update Firmware: Intel has fixed the issue in SPS_E3_04.01.04.700. and later. Download the latest from your server vendor or Intel directly.
- Restrict Local Access: Limit who can log in physically or remotely to servers — only trusted admins should have access.
- Monitor Logs: Watch for strange or repeated server/module crashes in your monitoring tools and investigate promptly.

More Resources

- Intel Security Advisory INTEL-SA-00702 (Original Advisory)
- NIST NVD Entry for CVE-2022-29466
- Server Platform Services (SPS) Documentation (Intel) *(may require login or vendor access)*

Conclusion

CVE-2022-29466 serves as a reminder that even low-level server management firmware is not immune to classic software bugs like improper input validation. While the exploit is limited to authenticated users physically or remotely present, the potential for downtime in sensitive environments should not be underestimated. Always update firmware and apply the principle of least privilege to your server environments.

Stay safe, keep systems patched, and monitor your logs for the unexpected!


*If you want to discuss firmware security or share your experience patching SPS systems, leave a comment below or ping us on social media!*

Timeline

Published on: 11/11/2022 16:15:00 UTC
Last modified on: 11/17/2022 14:30:00 UTC