CVE-2021-25130 – A local buffer overflow vulnerability in the Ba... (How to Fix)

Q: What is the severity of CVE-2021-25130?

CVE-2021-25130 has a CVSS score of 7.8 (HIGH). A local buffer overflow vulnerability in the Baseboard Management Controller (BMC) firmware for specific HPE Cloudline servers allows authenticated attackers to execute arbitrary code with elevated privileges. This affects HPE Cloudline CL5800 Gen9, CL5200 Gen9, CL4100 Gen10, CL3100 Gen10, and CL5800 Gen10 servers. The vulnerability exists in the spx_restservice setactdir_func function.

📋 TL;DR

A local buffer overflow vulnerability in the Baseboard Management Controller (BMC) firmware for specific HPE Cloudline servers allows authenticated attackers to execute arbitrary code with elevated privileges. This affects HPE Cloudline CL5800 Gen9, CL5200 Gen9, CL4100 Gen10, CL3100 Gen10, and CL5800 Gen10 servers. The vulnerability exists in the spx_restservice setactdir_func function.

💻 Affected Systems

Products:

HPE Cloudline CL5800 Gen9 Server
HPE Cloudline CL5200 Gen9 Server
HPE Cloudline CL4100 Gen10 Server
HPE Cloudline CL3100 Gen10 Server
HPE Cloudline CL5800 Gen10 Server

Versions: Specific BMC firmware versions prior to patched versions (check HPE advisory)

Operating Systems: Not applicable - BMC firmware vulnerability

Default Config Vulnerable: ⚠️ Yes

Notes: Requires authenticated access to the BMC interface. Affects only the listed HPE Cloudline server models with vulnerable BMC firmware.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete server compromise via remote code execution, allowing attacker to control the BMC, access host system, and potentially pivot to other systems.

🟠

Likely Case

Privilege escalation leading to BMC control, enabling persistent access, hardware manipulation, and potential data exfiltration.

🟢

If Mitigated

Limited impact if network segmentation and access controls prevent unauthorized BMC access.

🌐 Internet-Facing: MEDIUM - BMC interfaces should not be internet-facing, but misconfigurations could expose them.

🏢 Internal Only: HIGH - Internal attackers with BMC access can exploit this vulnerability to gain full control.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires authenticated access to the BMC interface. Buffer overflow exploitation typically requires some technical skill.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check HPE advisory for specific firmware versions

Vendor Advisory: https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf04073en_us

Restart Required: Yes

Instructions:

1. Download updated BMC firmware from HPE support portal. 2. Access BMC web interface. 3. Navigate to firmware update section. 4. Upload and apply the firmware update. 5. Reboot the server to complete installation.

🔧 Temporary Workarounds

Restrict BMC Network Access

all

Limit access to BMC management interfaces to trusted networks only using firewall rules.

Implement Strong Authentication

all

Use complex passwords and multi-factor authentication for BMC access.

🧯 If You Can't Patch

Isolate BMC management network from production networks
Monitor BMC access logs for suspicious activity

🔍 How to Verify

Check if Vulnerable:

Check BMC firmware version via BMC web interface or IPMI commands, compare against HPE advisory.

Check Version:

ipmitool mc info (requires IPMI access) or check BMC web interface

Verify Fix Applied:

Confirm BMC firmware version matches patched version listed in HPE advisory.

📡 Detection & Monitoring

Log Indicators:

Multiple failed authentication attempts to BMC
Unusual BMC firmware modification logs
Suspicious network connections to BMC port

Network Indicators:

Unusual traffic to BMC management port (default 443/623)
Anomalous outbound connections from BMC

SIEM Query:

source="BMC" AND (event_type="authentication_failure" OR event_type="firmware_update")

📊 Metadata

CVE ID: CVE-2021-25130

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-120

Published: January 29, 2021

Last Updated: November 21, 2024

🔗 References

https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf04073en_us Vendor Advisory
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf04073en_us Vendor Advisory

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