CVE-2021-3493
CVSS V2 High 7.2
CVSS V3 High 7.8
Description
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.
Overview
- CVE ID
- CVE-2021-3493
- Assigner
- security@ubuntu.com
- Vulnerability Status
- Analyzed
- Published Version
- 2021-04-17T05:15:14
- Last Modified Date
- 2022-10-27T12:43:16
Weakness Enumerations
CPE Configuration (Product)
| CPE | Vulnerable | Operator | Version Start | Version End |
|---|---|---|---|---|
| cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:* | 1 | OR | 18.04 | |
| cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:* | 1 | OR | 18.04.1 | 20.04 |
| cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:-:*:*:* | 1 | OR | 20.10 |
CVSS Version 2
- Version
- 2.0
- Vector String
- AV:L/AC:L/Au:N/C:C/I:C/A:C
- Access Vector
- LOCAL
- Access Compatibility
- LOW
- Authentication
- NONE
- Confidentiality Impact
- COMPLETE
- Integrity Impact
- COMPLETE
- Availability Impact
- COMPLETE
- Base Score
- 7.2
- Severity
- HIGH
- Exploitability Score
- 3.9
- Impact Score
- 10
CVSS Version 3
- Version
- 3.1
- Vector String
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Attack Vector
- LOCAL
- Attack Compatibility
- LOW
- Privileges Required
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality Impact
- HIGH
- Availability Impact
- HIGH
- Base Score
- 7.8
- Base Severity
- HIGH
- Exploitability Score
- 1.8
- Impact Score
- 5.9
References
| Reference URL | Reference Tags |
|---|---|
| https://www.openwall.com/lists/oss-security/2021/04/16/1 | Mailing List Third Party Advisory |
| https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52 | Mailing List Patch Third Party Advisory |
| https://ubuntu.com/security/notices/USN-4917-1 | Vendor Advisory |
| http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html | Exploit Third Party Advisory VDB Entry |
| http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html | Third Party Advisory VDB Entry |
| http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html | Exploit Third Party Advisory VDB Entry |
Sources
| Source Name | Source URL |
|---|---|
| NIST | https://nvd.nist.gov/vuln/detail/CVE-2021-3493 |
| MITRE | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3493 |
History
| Created | Old Value | New Value | Data Type | Notes |
|---|---|---|---|---|
| 2022-05-10 06:40:57 | Added to TrackCVE | |||
| 2022-12-06 02:04:41 | 2021-04-17T05:15Z | 2021-04-17T05:15:14 | CVE Published Date | updated |
| 2022-12-06 02:04:41 | 2022-10-27T12:43:16 | CVE Modified Date | updated | |
| 2022-12-06 02:04:41 | Analyzed | Vulnerability Status | updated |