CVE-2016-2781
Published: February 7, 2017Last modified: July 22, 2025
Description
chroot in GNU coreutils, when used with --userspec, allows local users to escape to the parent session via a crafted TIOCSTI ioctl call, which pushes characters to the terminal's input buffer.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 4.6 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | REQUIRED |
| Scope | CHANGED |
| Confidentiality | LOW |
| Integrity impact | LOW |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
Notes
The fix reverted in coreutils http://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=f5d7c0842ef7adc2be6e85f9ef66b35ebbbd6a61, with the following statement: "This reverts commit v8.27-97-g8cb06d4 because the setsid() fallback was not implemented correctly and disabling the ioctl was not a complete solution to the security issue of the child being passed the tty of the parent. Given runcon is not really a sandbox command, the advice is to use `runcon ... setsid ...` to avoid this particular issue."
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | Stream | coreutils | Will not fix (9.1-r0) |
| Hardened Containers | Stream | coreutils | Will not fix (9.1-r0) |