grub2 — security advisory
A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
- Products
- grub2
- Affected versions
- Not specified
- Fixed versions
- 2.06-3
- CVEs
- CVE-2021-3697
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:37 UTC · Revision 1
Source evidence
A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
osv:DEBIAN-CVE-2021-3697
grub2
Fixed versions: 2.06-3
grub2
Fixed versions: 2.06-3
grub2
Fixed versions: 2.06-3
Complete source record
{
"id": "f42c9af990b39ddf0d50d34b4695cca2d7b00915fc911b457f17ab721e1b0568",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-3697",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-3697",
"summary": "A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.",
"evidence": "osv:DEBIAN-CVE-2021-3697",
"products": [
{
"name": {
"value": "grub2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.06-3",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "grub2",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.06-3",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "grub2",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.06-3",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2021-3697",
"aliases": [
"DEBIAN-CVE-2021-3697"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.06-3"
}
]
}
],
"package": {
"name": "grub2",
"purl": "pkg:deb/debian/grub2?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3697.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.06-3"
}
]
}
],
"package": {
"name": "grub2",
"purl": "pkg:deb/debian/grub2?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3697.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.06-3"
}
]
}
],
"package": {
"name": "grub2",
"purl": "pkg:deb/debian/grub2?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3697.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:03:29.743516047Z",
"provider": "osv",
"upstream": [
"CVE-2021-3697"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-3697"
]
},
"related_cves": [
{
"value": "CVE-2021-3697",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 421689,
"published_at": "2022-07-06T16:15:08.32+00:00"
}