Cybersecurity researchers have uncovered two significant vulnerabilities in Supermicro’s Baseboard Management Controller (BMC) firmware that could enable attackers to install malicious firmware by circumventing critical security checks.
## The Vulnerabilities
The two medium-severity flaws, both stemming from inadequate cryptographic signature verification, are:
**CVE-2025-7937 (CVSS: 6.6)**: Attackers can bypass Root of Trust (RoT) 1.0 verification by redirecting the system to a fake “fwmap” table in an unsigned region of specially crafted firmware.
**CVE-2025-6198 (CVSS: 6.4)**: Similar bypass technique targeting the Signing Table verification process using a fake “sig_table” in the unsigned region.
## How the Attack Works
Supermicro’s firmware validation process follows three steps:
1. Retrieve the public key from the BMC flash chip
2. Process the embedded “fwmap” or “sig_table” from the uploaded image
3. Calculate and verify cryptographic signatures against firmware regions
The vulnerabilities exploit weaknesses in this process. Attackers can insert custom tables before the original ones, manipulating the validation logic while maintaining matching hash values by relocating original signed content to unused firmware space.
## Research Background
Firmware security firm Binarly discovered these flaws, with CVE-2025-7937 representing a bypass for a previously patched vulnerability (CVE-2024-10237) that was originally found by NVIDIA. The researchers determined that Supermicro’s initial fix was insufficient, leaving systems vulnerable to new attack methods.
## Serious Security Implications
Successful exploitation grants attackers complete control over both the BMC system and the main server operating system. The vulnerabilities also bypass BMC Root of Trust security features, contradicting previous assurances from Supermicro about hardware-level protection.
“Any leak of the signing key will impact the entire ecosystem,” warned Alex Matrosov, CEO of Binarly. The company recommends rotating signing keys per product line to minimize industry-wide risks, citing previous incidents like PKfail and Intel Boot Guard key leakage.
## The Bigger Picture
These discoveries highlight ongoing challenges in firmware security, particularly around cryptographic verification processes. The ability to bypass Root of Trust protections represents a significant escalation in potential attack sophistication, emphasizing the critical importance of robust firmware validation mechanisms in enterprise hardware.
Organizations using affected Supermicro systems should monitor for security updates and consider implementing additional network-level protections while patches are developed and deployed.