github - ghsa-2fj2-4h38-3c72

GHSA-2FJ2-4H38-3C72

Vulnerability from github – Published: 2022-05-24 17:47 – Updated: 2025-10-22 00:32

Details

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.

Severity ?

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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  "aliases": [
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  ],
  "database_specific": {
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    "github_reviewed_at": null,
    "nvd_published_at": "2021-04-17T05:15:00Z",
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  "id": "GHSA-2fj2-4h38-3c72",
  "modified": "2025-10-22T00:32:06Z",
  "published": "2022-05-24T17:47:46Z",
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CVE-2021-3493 (GCVE-0-2021-3493)

Vulnerability from cvelistv5 – Published: 2021-04-17 04:20 – Updated: 2025-10-21 23:25

Summary

Severity ?

8.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CWE

CWE-270 - Privilege Context Switching Error

Assigner

canonical

References

URL

Tags

	https://ubuntu.com/security/notices/USN-4917-1	x_refsource_MISC
	https://git.kernel.org/pub/scm/linux/kernel/git/t…	x_refsource_MISC
	https://www.openwall.com/lists/oss-security/2021/…	x_refsource_MISC
	http://packetstormsecurity.com/files/162434/Kerne…	x_refsource_MISC
	http://packetstormsecurity.com/files/162866/Ubunt…	x_refsource_MISC
	http://packetstormsecurity.com/files/165151/Ubunt…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	Ubuntu	linux kernel	Affected: 5.8 kernel , < 5.8.0-50.56 (custom) Affected: 5.4 kernel , < 5.4.0-72.80 (custom) Affected: 4.15 kernel , < 4.15.0-142.146 (custom) Affected: 4.4 kernel , < 4.4.0-209.241 (custom)

Credits

An independent security researcher reporting to the SSD Secure Disclosure program

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JSON

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Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-2FJ2-4H38-3C72

CVE-2021-3493 (GCVE-0-2021-3493)

Tags

Sightings

Nomenclature