cbcvebase.
CVE-2017-1000367
published 2017-06-05

CVE-2017-1000367: Todd Miller's sudo version 1.8.20 and earlier is vulnerable to an input validation (embedded spaces) in the get_process_ttyname() function resulting in…

PriorityP275medium6.4CVSS 3.0
AVLACHPRHUINSUCHIHAH
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
8.02%
94.1th percentile
Todd Miller's sudo version 1.8.20 and earlier is vulnerable to an input validation (embedded spaces) in the get_process_ttyname() function resulting in information disclosure and command execution.

Affected

6 ranges
VendorProductVersion rangeFixed in
debiansudo< sudo 1.8.20p1-1 (bookworm)sudo 1.8.20p1-1 (bookworm)
sudo_projectsudo<= 1.8.20
sudo_projectsudo>= 0 < 1.8.20p1-11.8.20p1-1
sudo_projectsudo>= 0 < 1.8.20p1-11.8.20p1-1
sudo_projectsudo>= 0 < 1.8.20p1-11.8.20p1-1
sudo_projectsudo>= 0 < 1.8.20p1-11.8.20p1-1

Detection & IOCsextracted from sources · hover to see the quote

path/usr/bin/sudo
  • Monitor for creation of the working directory /dev/shm/_tmp and symlink /dev/shm/_tmp/_tty, which are hardcoded artifacts of the CVE-2017-1000367 exploit.
  • Detect rapid creation and renaming of symlinks under /dev/shm targeting /dev/pts/* devices, indicative of the TTY symlink race condition exploitation technique used in this CVE.
  • Monitor /proc/<pid>/stat reads by sudo combined with embedded spaces in the tty field, as the vulnerability is triggered by input validation failure in get_process_ttyname() parsing of /proc status files.
  • Detect sudo invocations with an SELinux role argument (e.g., unconfined_r) from non-privileged users, as the exploit requires sudo to be run with a role to trigger the vulnerable code path.
  • Detect mass opening of /dev/pts/* pseudo-terminal devices (up to 64 fds, PTS_NUM=32 pairs) by a single non-root process, which is used to predict and control the tty device number during exploitation.
  • ·The exploit targets sudo version 1.8.20 and earlier; systems running sudo 1.8.20p1-1 or later (as fixed in Debian) are not vulnerable to CVE-2017-1000367, though CVE-2017-1000368 covers an incomplete fix in 1.8.20p1 and earlier.
  • ·The exploit is only effective on Linux systems with SELinux enabled; the privilege escalation path requires the ability to pass a role argument to sudo.
  • ·When combined with the Stack Clash (CVE-2017-1000364), any local user (not just sudoers) can exploit sudo to obtain full root privileges, broadening the affected population beyond SELinux-only scenarios.
  • ·The RLIMIT_STACK/RLIMIT_AS workaround is unreliable; the Sudo stack-clash exploit variant may allocate as little as 137MB of heap memory and nearly no stack memory, potentially bypassing low resource limits.

CVSS provenance

nvdv3.06.4MEDIUMCVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
nvdv2.06.9MEDIUMAV:L/AC:M/Au:N/C:C/I:C/A:C
osv6.4MEDIUM
vulncheck6.4MEDIUM
vendor_debian6.4MEDIUM
vendor_redhat6.4MEDIUM
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