CVE-2009-4128
Published Dec 1, 2009 · Updated Nov 3, 2026
Original summary
Normalized public record · Updated Nov 3, 2026
GNU GRand Unified Bootloader (GRUB) 2 1.97 only compares the submitted portion of a password with the actual password, which makes it easier for physically proximate attackers to conduct brute force attacks and bypass authentication by submitting a password whose length is 1.
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
GNU GRand Unified Bootloader (GRUB) 2 1.97 only compares the submitted portion of a password with the actual password, which makes it easier for physically proximate attackers to conduct brute force attacks and bypass authentication by submitting a password whose length is 1.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
- bugs.debian.org ↗
- 36968 ↗
- gnugrub2-password-auth-bypass(54210) ↗
- [oss-security] 20240116 CVE-2023-4001: a password bypass vulnerability in the downstream GRUB boot manager ↗
Record history
Published Dec 1, 2009 · Last refreshed Nov 3, 2026