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2 vulnerabilities found for linux kernel by Ubuntu
CVE-2021-3493 (GCVE-0-2021-3493)
Vulnerability from nvd
Published
2021-04-17 04:20
Modified
2025-10-21 23:25
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-270 - Privilege Context Switching Error
Summary
The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Ubuntu | linux kernel |
Version: 5.8 kernel < 5.8.0-50.56 Version: 5.4 kernel < 5.4.0-72.80 Version: 4.15 kernel < 4.15.0-142.146 Version: 4.4 kernel < 4.4.0-209.241 |
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CVE-2021-3493 (GCVE-0-2021-3493)
Vulnerability from cvelistv5
Published
2021-04-17 04:20
Modified
2025-10-21 23:25
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-270 - Privilege Context Switching Error
Summary
The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.
References
| URL | Tags | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||||||||||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Ubuntu | linux kernel |
Version: 5.8 kernel < 5.8.0-50.56 Version: 5.4 kernel < 5.4.0-72.80 Version: 4.15 kernel < 4.15.0-142.146 Version: 4.4 kernel < 4.4.0-209.241 |
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"refsource": "MISC",
"url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"
},
{
"name": "https://www.openwall.com/lists/oss-security/2021/04/16/1",
"refsource": "MISC",
"url": "https://www.openwall.com/lists/oss-security/2021/04/16/1"
},
{
"name": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html",
"refsource": "MISC",
"url": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html"
},
{
"name": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html",
"refsource": "MISC",
"url": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html"
},
{
"name": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html",
"refsource": "MISC",
"url": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html"
}
]
},
"solution": [
{
"lang": "en",
"value": "Apply https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"
}
],
"source": {
"discovery": "EXTERNAL"
},
"work_around": [
{
"lang": "en",
"value": "Disable unprivileged user namespaces."
}
]
}
}
},
"cveMetadata": {
"assignerOrgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
"assignerShortName": "canonical",
"cveId": "CVE-2021-3493",
"datePublished": "2021-04-17T04:20:16.706Z",
"dateReserved": "2021-04-12T00:00:00.000Z",
"dateUpdated": "2025-10-21T23:25:48.908Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}