CVE-2016-1575
The overlayfs implementation in the Linux kernel through 4.5.2 does not properly maintain POSIX ACL xattr data, which allows local users to gain privileges by leveraging a group-writable setgid directory.
Does this matter?
A public exploit is published in Exploit-DB and the impact is high, while EPSS rates exploitation at 0.9%. Anyone can run this; patch or mitigate before the next change window and check exposed instances for signs of use.
Description
The overlayfs implementation in the Linux kernel through 4.5.2 does not properly maintain POSIX ACL xattr data, which allows local users to gain privileges by leveraging a group-writable setgid directory.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.92% probability · 60th percentile
- Public exploits
- 1 in Exploit-DB · first 22 November 2016
- CISA KEV
- Not listed
- Weakness
- CWE-269
- Affected
- linux/linux kernel · canonical/ubuntu core · canonical/ubuntu linux · canonical/ubuntu touch
- Source
- security@ubuntu.com
EPSS 0.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e9f57ebcba563e0cd532926cab83c92bb4d79360Patch, Vendor Advisory
- http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-1575.htmlThird Party Advisory
- http://www.halfdog.net/Security/2016/UserNamespaceOverlayfsXattrSetgidPrivilegeEscalation/Exploit, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2016/02/24/7Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/18/1Mailing List, Third Party Advisory
- https://launchpad.net/bugs/1534961Third Party Advisory
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e9f57ebcba563e0cd532926cab83c92bb4d79360Patch, Vendor Advisory
- http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-1575.htmlThird Party Advisory
- http://www.halfdog.net/Security/2016/UserNamespaceOverlayfsXattrSetgidPrivilegeEscalation/Exploit, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2016/02/24/7Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/18/1Mailing List, Third Party Advisory
- https://launchpad.net/bugs/1534961Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.