CVE-2021-20225
No exploitation reported by the sources we read.
- Published2021-03-03
- WeaknessCWE-787
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
A flaw was found in grub2 in versions prior to 2.06. The option parser allows an attacker to write past the end of a heap-allocated buffer by calling certain commands with a large number of specific short forms of options. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Timeline
dates in UTC- 2021-03-0317:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-20225?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-20225?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 7.2 | = 7.2 | no fix published | NVD |
| 7.3 | = 7.3 | no fix published | NVD |
| 7.4 | = 7.4 | no fix published | NVD |
| 7.6 | = 7.6 | no fix published | NVD |
| 7.7 | = 7.7 | no fix published | NVD |
| 8.2 | = 8.2 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 7.4 | = 7.4 | no fix published | NVD |
| 7.6 | = 7.6 | no fix published | NVD |
| 7.7 | = 7.7 | no fix published | NVD |
| 8.2 | = 8.2 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 7.6 | = 7.6 | no fix published | NVD |
| 7.7 | = 7.7 | no fix published | NVD |
| 8.1 | = 8.1 | no fix published | NVD |
5 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Packages
- shim-unsigned-aarch64AlmaLinux:8all versions · fixed in 15-7.el8_1.alma
- shim-unsigned-x64AlmaLinux:8all versions · fixed in 15.4-4.el8_1.alma
- shim-x64AlmaLinux:8all versions · fixed in 15.4-2.el8_1.almaand 2 other packages
Fix
No fix published by the sources we read yet. NVD record
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- Published
- 2021-03-03
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-20225?
Is CVE-2021-20225 actively exploited?
What is the CVSS score for CVE-2021-20225?
Running shim-x64? Hear about its next vulnerability
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.