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CVE

CVE-2021-3493

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.
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CVE

CVE-2021-3493

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.

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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
8.8
-
3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
C
H
U
-

Related Resources

No items found.

References

http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html, https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-3493, http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html, http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html, http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html, https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52, https://ubuntu.com/security/notices/USN-4917-1, https://www.openwall.com/lists/oss-security/2021/04/16/1, https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52, https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52, https://www.openwall.com/lists/oss-security/2021/04/16/1, http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html, http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html

Severity

7.8

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
7.8
EPSS Probability
0.76767%
EPSS Percentile
0.98916%
Introduced Version
0
Fix Available
7c03e2cda4a584cadc398e8f6641ca9988a39d52,5.10.38-1,0:4.15.0-142.146,0:5.3.0-73.69,0:5.4.0-72.80~18.04.1,0:4.15.0-1090.92,0:4.15.0-1099.106,0:5.4.0-1045.47~18.04.1,0:4.15.0-1113.126,0:5.4.0-1046.48~18.04.1,0:4.15.0-1017.21,0:4.15.0-1098.111,0:5.4.0-1042.45~18.04.1,0:5.3.0-1042.45,0:5.4.0-1042.44~18.04.1,0:5.4.0-1014.15~18.04.1,0:4.15.0-1070.78,0:5.4.0-1043.46~18.04.1,0:4.15.0-1084.89,0:5.3.0-1039.41,0:5.4.0-1034.37~18.04.1,0:4.15.0-1101.110,0:5.4.0-72.80,0:5.8.0-50.56~20.04.1,0:5.4.0-1038.39,0:5.4.0-1045.47,0:5.4.0-1046.48,0:5.4.0-1042.45,0:5.4.0-1014.15,0:5.4.0-1043.46,0:5.6.0-1054.58,0:5.10.0-1022.23,0:5.4.0-1034.37,0:5.4.0-1042.44

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