CVE-2021-3849An authentication bypass vulnerability was discovered in the web interface of the Lenovo Fan Power Controller2 (FPC2) and Lenovo System…
- 9.8CriticalCVSS base score
- 1.3%Exploitation in 30 daysEPSS · top 29% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
An authentication bypass vulnerability was discovered in the web interface of the Lenovo Fan Power Controller2 (FPC2) and Lenovo System Management Module (SMM) firmware that could allow an unauthenticated attacker to execute commands on the SMM and FPC2. SMM2 is not affected.
Timeline
ID reserved
By lenovo
- 7 months later
· 7 months later
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| lenovoCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.3% · top 29% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
Lenovo · Fan Power Controller2 (FPC2)
- affected various
Lenovo · Lenovo System Management Module (SMM)
- affected various
What to do
Solution: Upgrade to the firmware version (or newer) indicated for your model in the Product Impact section in LEN-72615.
References
References1
- https://support.lenovo.com/us/en/product_security/LEN-72615 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-27091 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-3849)Record last updated .